Catalyst composition and methods for its preparation and use in a polymerization and use in a polymerization process

ABSTRACT

The present invention relates to a catalyst composition and a method for making the catalyst composition of a polymerization catalyst and a carboxylate metal salt. The invention is also directed to the use of the catalyst composition in the polymerization of olefin(s). In particular, the polymerization catalyst system is supported on a carrier. More particularly, the polymerization catalyst comprises a bulky ligand metallocene-type catalyst system.

RELATED APPLICATION DATA

[0001] The present is a Divisional of U.S. application Ser. No.09/397,410, filed Sep. 16, 1999, now issued as U.S. Pat. No. ______,which is a continuation-in-part of U.S. patent application Ser. No.09/113,216, filed Jul. 10, 1998.

FIELD OF THE INVENTION

[0002] The present invention relates to a catalyst composition andmethods for preparing the catalyst composition and for its use in aprocess for polymerizing olefins. In particular, the invention isdirected to a method for preparing a catalyst composition of a bulkyligand metallocene-type catalyst system and/or a conventional-typetransition metal catalyst system, and a carboxylate metal salt.

BACKGROUND OF THE INVENTION

[0003] Advances in polymerization and catalysis have resulted in thecapability to produce many new polymers having improved physical andchemical properties useful in a wide variety of superior products andapplications. With the development of new catalysts the choice ofpolymerization-type (solution, slurry, high pressure or gas phase) forproducing a particular polymer has been greatly expanded. Also, advancesin polymerization technology have provided more efficient, highlyproductive and economically enhanced processes. Especially illustrativeof these advances is the development of technology utilizing bulkyligand metallocene-type catalyst systems. Regardless of thesetechnological advances in the polyolefin industry, common problems, aswell as new challenges associated with process operability still exist.For example, the tendency for a gas phase or slurry phase process tofoul and/or sheet remains a challenge.

[0004] For example, in a continuous slurry process fouling on the wallsof the reactor, which act as a heat transfer surface, can result in manyoperability problems. Poor heat transfer during polymerization canresult in polymer particles adhering to the walls of the reactor. Thesepolymer particles can continue to polymerize on the walls and can resultin a premature reactor shutdown. Also, depending on the reactorconditions, some of the polymer may dissolve in the reactor diluent andredeposit on for example the metal heat exchanger surfaces.

[0005] In a typical continuous gas phase process, a recycle system isemployed for many reasons including the removal of heat generated in theprocess by the polymerization. Fouling, sheeting and/or staticgeneration in a continuous gas phase process can lead to the ineffectiveoperation of various reactor systems. For example, the cooling mechanismof the recycle system, the temperature probes utilized for processcontrol and the distributor plate, if affected, can lead to an earlyreactor shutdown.

[0006] Evidence of, and solutions to, various process operabilityproblems have been addressed by many in the art. For example, U.S. Pat.Nos. 4,792,592, 4,803,251, 4,855,370 and 5,391,657 all discusstechniques for reducing static generation in a polymerization process byintroducing to the process for example, water, alcohols, ketones, and/orinorganic chemical additives; PCT publication WO 97/14721 published Apr.24, 1997 discusses the suppression of fines that can cause sheeting byadding an inert hydrocarbon to the reactor; U.S. Pat. No. 5,627,243discusses a new type of distributor plate for use in fluidized bed gasphase reactors; PCT publication WO 96/08520 discusses avoiding theintroduction of a scavenger into the reactor; U.S. Pat. No. 5,461,123discusses using sound waves to reduce sheeting; U.S. Pat. No. 5,066,736and EP-A1 0 549 252 discuss the introduction of an activity retarder tothe reactor to reduce agglomerates; U.S. Pat. No. 5,610,244 relates tofeeding make-up monomer directly into the reactor above the bed to avoidfouling and improve polymer quality; U.S. Pat. No. 5,126,414 discussesincluding an oligomer removal system for reducing distributor platefouling and providing for polymers free of gels; EP-A1 0 453 116published Oct. 23, 1991 discusses the introduction of antistatic agentsto the reactor for reducing the amount of sheets and agglomerates; U.S.Pat. No. 4,012,574 discusses adding a surface-active compound, aperfluorocarbon group, to the reactor to reduce fouling; U.S. Pat. No.5,026,795 discusses the addition of an antistatic agent with a liquidcarrier to the polymerization zone in the reactor; U.S. Pat. No.5,410,002 discusses using a conventional Ziegler-Nattatitanium/magnesium supported catalyst system where a selection ofantistatic agents are added directly to the reactor to reduce fouling;U.S. Pat. Nos. 5,034,480 and 5,034,481 discuss a reaction product of aconventional Ziegler-Natta titanium catalyst with an antistat to produceultrahigh molecular weight ethylene polymers; U.S. Pat. No. 3,082,198discusses introducing an amount of a carboxylic acid dependent on thequantity of water in a process for polymerizing ethylene using atitanium/aluminum organometallic catalysts in a hydrocarbon liquidmedium; and U.S. Pat. No. 3,919,185 describes a slurry process using anonpolar hydrocarbon diluent using a conventional Ziegler-Natta-type orPhillips-type catalyst and a polyvalent metal salt of an organic acidhaving a molecular weight of at least 300.

[0007] There are various other known methods for improving operabilityincluding coating the polymerization equipment, for example, treatingthe walls of a reactor using chromium compounds as described in U.S.Pat. Nos. 4,532,311 and 4,876,320; injecting various agents into theprocess, for example PCT Publication WO 97/46599 published December 11,1997 discusses feeding into a lean zone in a polymerization reactor anunsupported, soluble metallocene-type catalyst system and injectingantifoulants or antistatic agents into the reactor; controlling thepolymerization rate, particularly on start-up; and reconfiguring thereactor design.

[0008] Others in the art to improve process operability have discussedmodifying the catalyst system by preparing the catalyst system indifferent ways. For example, methods in the art include combining thecatalyst system components in a particular order; manipulating the ratioof the various catalyst system components; varying the contact timeand/or temperature when combining the components of a catalyst system;or simply adding various compounds to the catalyst system. Thesetechniques or combinations thereof are discussed in the literature.Especially illustrative in the art is the preparation procedures andmethods for producing bulky ligand metallocene-type catalyst systems,more particularly supported bulky ligand metallocene-type catalystsystems with reduced tendencies for fouling and better operability.Examples of these include: WO 96/11961 published Apr. 26, 1996 discussesas a component of a supported catalyst system an antistatic agent forreducing fouling and sheeting in a gas, slurry or liquid poolpolymerization process; U.S. Pat. No. 5,283,278 is directed towards theprepolymerization of a metallocene catalyst or a conventionalZiegler-Natta catalyst in the presence of an antistatic agent; U.S. Pat.Nos. 5,332,706 and 5,473,028 have resorted to a particular technique forforming a catalyst by incipient impregnation; U.S. Pat. Nos. 5,427,991and 5,643,847 describe the chemical bonding of non-coordinating anionicactivators to supports; U.S. Pat. No. 5,492,975 discusses polymer boundmetallocene-type catalyst systems; U.S Pat. No. 5,661,095 discussessupporting a metallocene-type catalyst on a copolymer of an olefin andan unsaturated silane; PCT publication WO 97/06186 published Feb. 20,1997 teaches removing inorganic and organic impurities after formationof the metallocene-type catalyst itself, PCT publication WO 97/15602published May 1, 1997 discusses readily supportable metal complexes; PCTpublication WO 97/27224 published Jul. 31, 1997 relates to forming asupported transition metal compound in the presence of an unsaturatedorganic compound having at least one terminal double bond; and EP-A2-811638 discusses using a metallocene catalyst and an activating cocatalystin a polymerization process in the presence of a nitrogen containingantistatic agent.

[0009] While all these possible solutions might reduce the level offouling or sheeting somewhat, some are expensive to employ and/or maynot reduce fouling and sheeting to a level sufficient to successfullyoperate a continuous process, particularly a commercial or large-scaleprocess.

[0010] Thus, it would be advantageous to have a polymerization processcapable of operating continuously with enhanced reactor operability andat the same time produce new and improved polymers. It would also behighly beneficial to have a continuously operating polymerizationprocess having more stable catalyst productivities, reducedfouling/sheeting tendencies and increased duration of operation.

SUMMARY OF THE INVENTION

[0011] This invention provides a method of making a new and improvedcatalyst composition and for its use in a polymerizing process. Themethod comprises the step of combining, contacting, blending and/ormixing a catalyst system, preferably a supported catalyst system, with acarboxylate metal salt. In one embodiment the catalyst system comprisesa conventional-type transition metal catalyst compound. In the mostpreferred embodiment the catalyst system comprises a bulky ligandmetallocene-type catalyst compound. The combination of the catalystsystem and the carboxylate metal salt is useful in any olefinpolymerization process. The preferred polymerization processes are a gasphase or a slurry phase process, most preferably a gas phase process.

[0012] In an embodiment, the invention provides for a method of making acatalyst composition useful for the polymerization of olefin(s), themethod including combining, contacting, blending and/or mixing apolymerization catalyst with at least one carboxylate metal salt. In anembodiment, the polymerization catalyst is a conventional-typetransition metal polymerization catalyst, more preferably a supportedconventional-type transition metal polymerization catalyst. In the mostpreferred embodiment, the polymerization catalyst is a bulky ligandmetallocene-type catalyst, most preferably a supported bulky ligandmetallocene-type polymerization catalyst.

[0013] In one preferred embodiment, the invention is directed to acatalyst composition comprising a catalyst compound, preferably aconventional-type transition metal catalyst compound, more preferably abulky ligand metallocene-type catalyst compound, an activator and/orcocatalyst, a carrier, and a carboxylate metal salt.

[0014] In the most preferred method of the invention, the carboxylatemetal salt is blended, preferably dry blended, and most preferablytumble dry blended or fluidized, with a supported catalyst system orpolymerization catalyst comprising a carrier. In this most preferredembodiment, the polymerization catalyst includes at least one bulkyligand metallocene-type catalyst compound, an activator and a carrier.

[0015] In yet another embodiment, the invention relates to a process forpolymerizing olefin(s) in the presence of a catalyst compositioncomprising a polymerization catalyst and a carboxylate metal salt,preferably the polymerization catalyst comprises a carrier, morepreferably the polymerization catalyst comprises one or more ofcombination of a conventional-type catalyst compound and/or a bulkyligand metallocene-type catalyst compound.

[0016] In a preferred method for making the catalyst composition of theinvention, the method comprises the steps of combining a bulky ligandmetallocene-type catalyst compound, an activator and a carrier to form asupported bulky ligand metallocene-type catalyst system, and contactingthe supported bulky ligand metallocene-type catalyst compound with acarboxylate metal salt. In the most preferred embodiment, the supportedbulky ligand metallocene-type catalyst system and the carboxylate metalsalt are in a substantially dry state or dried state.

[0017] In an embodiment, the invention provides for a process forpolymerizing olefin(s) in the presence of a polymerization catalysthaving been combined, contacted, blended, or mixed with at least onecarboxylate metal salt.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Introduction

[0019] The invention is directed toward a method for making a catalystcomposition and to the catalyst composition itself. The invention alsorelates to a polymerization process having improved operability andproduct capabilities using the catalyst composition. It has beensuprisingly discovered that using a carboxylate metal salt incombination with a catalyst system results in a substantially improvedpolymerization process. Particularly surprising is where the catalystsystem is supported on carrier, more so where the catalyst systemincludes a bulky ligand metallocene-type catalyst system, and even moreso where the bulky ligand metallocene-type catalysts are very activeand/or are highly incorporating of comonomer.

[0020] While not wishing to be bound by any theory, it is believed thatthese bulky ligand metallocene-type catalysts are more prone to sheetingand/or fouling. It is believed that the very high activity catalysts canresult in the generation of extreme heat local to the growing polymerparticle. It is theorized that these extreme conditions lead toincreased levels of sheeting and/or fouling. Also hypothesized is thatthe polymers produced by bulky ligand metallocene-type catalysts formvery tough polymer sheets. Thus, it is difficult to break-up and removeany of these sheets that may form in the reactor.

[0021] Furthermore, it was very unexpected that fractional melt indexand higher density polymers could be produced in a polymerizationprocess using the polymerization catalyst and carboxylate metal saltcombination with improved operability. This discovery was especiallyimportant in that it is well known in the polymer industry that, from aprocess operability standpoint, these types of polymers are difficult toproduce.

[0022] Utilizing the polymerization catalysts described below incombination with a carboxylate metal salt results in a substantialimprovement in process operability, a significant reduction in sheetingand fouling, improved catalyst performance, better polymer particlemorphology with no adverse effect on the physical polymer properties,and the capability to produce a broader range of polymers.

[0023] Catalyst Components and Catalyst Systems

[0024] All polymerization catalysts including conventional-typetransition metal catalysts are suitable for use in the polymerizingprocess of the invention. However, processes using bulky ligand and/orbridged bulky ligand, metallocene-type catalysts are particularlypreferred. The following is a non-limiting discussion of the variouspolymerization catalysts useful in the invention.

[0025] Conventional-type Transition Metal Catalysts

[0026] Conventional-type transition metal catalysts are thosetraditional Ziegler-Natta catalysts and Phillips-type chromium catalystwell known in the art. Examples of conventional-type transition metalcatalysts are discussed in U.S. Pat. Nos. 4,115,639, 4,077,904,4,482,687, 4,564,605, 4,721,763, 4,879,359 and 4,960,741 all of whichare herein fully incorporated by reference. The conventional-typetransition metal catalyst compounds that may be used in the presentinvention include transition metal compounds from Groups III to VIII,preferably IVB to VIB of the Periodic Table of Elements.

[0027] These conventional-type transition metal catalysts may berepresented by the formula: MR_(x), where M is a metal from Groups IIIBto VIII, preferably Group IVB, more preferably titanium; R is a halogenor a hydrocarbyloxy group; and x is the valence of the metal M.Non-limiting examples of R include alkoxy, phenoxy, bromide, chlorideand fluoride. Non-limiting examples of conventional-type transitionmetal catalysts where M is titanium include TiCl₄, TiBr₄, Ti(OC₂H₅)₃Cl,Ti(OC₂H₅)Cl₃, Ti(OC₄H₉)₃Cl, Ti(OC₃H₇)₂Cl₂, Ti(OC₂H₅)₂Br₂, TiCl₃.1/3AlCl₃and Ti(OC₁₂H₂₅)Cl₃.

[0028] Conventional-type transition metal catalyst compounds based onmagnesium/titanium electron-donor complexes that are useful in theinvention are described in, for example, U.S. Pat. Nos. 4,302,565 and4,302,566, which are herein fully incorporate by reference. The MgTiCl₆(ethyl acetate)₄ derivative is particularly preferred. British PatentApplication 2,105,355, herein incorporated by reference, describesvarious conventional-type vanadium catalyst compounds. Non-limitingexamples of conventional-type vanadium catalyst compounds includevanadyl trihalide, alkoxy halides and alkoxides such as VOCl₃,VOCl₂(OBu) where Bu is butyl and VO(OC₂H₅)₃; vanadium tetra-halide andvanadium alkoxy halides such as VCl₄ and VCl₃(OBu); vanadium and vanadylacetyl acetonates and chloroacetyl acetonates such as V(AcAc)₃ andVOCl₂(AcAc) where (AcAc) is an acetyl acetonate. The preferredconventional-type vanadium catalyst compounds are VOCl₃, VCl₄ andVOCl₂—OR where R is a hydrocarbon radical, preferably a C₁ to C₁₀aliphatic or aromatic hydrocarbon radical such as ethyl, phenyl,isopropyl, butyl, propyl, n-butyl, iso-butyl, tertiary-butyl, hexyl,cyclohexyl, naphthyl, etc., and vanadium acetyl acetonates.

[0029] Conventional-type chromium catalyst compounds, often referred toas Phillips-type catalysts, suitable for use in the present inventioninclude CrO₃, chromocene, silyl chromate, chromyl chloride (CrO₂Cl₂),chromium-2-ethyl-hexanoate, chromium acetylacetonate (Cr(AcAc)₃), andthe like. Non-limiting examples are disclosed in U.S. Pat. Nos.2,285,721, 3,242,099 and 3,231,550, which are herein fully incorporatedby reference.

[0030] Still other conventional-type transition metal catalyst compoundsand catalyst systems suitable for use in the present invention aredisclosed in U.S. Pat. Nos. 4,124,532, 4,302,565, 4,302,566 and5,763,723 and published EP-A2 0 416 815 A2 and EP-A1 0 420 436, whichare all herein incorporated by reference. The conventional-typetransition metal catalysts of the invention may also have the generalformula M′_(t)M″X_(2t)Y_(u)E, where M′ is Mg, Mn and/or Ca; t is anumber from 0.5 to 2; M″ is a transition metal Ti, V and/or Zr; X is ahalogen, preferably Cl, Br or I; Y may be the same or different and ishalogen, alone or in combination with oxygen, —NR₂, —OR, —SR, —COOR, or—OSOOR, where R is a hydrocarbyl radical, in particular an alkyl, aryl,cycloalkyl or arylalkyl radical, acetylacetonate anion in an amount thatsatisfies the valence state of M′; u is a number from 0.5 to 20; E is anelectron donor compound selected from the following classes ofcompounds: (a) esters of organic carboxylic acids; (b) alcohols; (c)ethers; (d) amines; (e) esters of carbonic acid; (f) nitriles; (g)phosphoramides, (h) esters of phosphoric and phosphorus acid, and (j)phosphorus oxy-chloride. Non-limiting examples of complexes satisfyingthe above formula include: MgTiCl₅.2CH₃COOC₂H₅, Mg₃Ti₂Cl₁₂.7CH₃COOC₂H₅,MgTiCl₅.6C₂H₅OH, MgTiCl₅.100CH₃OH, MgTiCl₅.tetrahydrofuran,MgTi₂Cl₁₂.7C₆H₅CN, Mg₃Ti₂Cl₁₂.6C₆H₅COOC₂H₅, MgTiCl₆.2CH₃COOC₂H₅,MgTiCl₆.6C₅H₅N, MgTiCl₅(OCH₃).2CH₃COOC₂H₅, MgTiCl₅N(C₆H₅)₂.3CH₃COOC₂H₅,MgTiBr₂Cl₄.2(C₂H₅)₂O, MnTiCl₅.4C₂H₅OH, Mg₃V₂Cl₁₂.7CH₃COOC₂H₅, MgZrCl₆4tetrahydrofuran. Other catalysts may include cationic catalysts such asAlCl₃, and other cobalt and iron catalysts well known in the art.

[0031] Typically, these conventional-type transition metal catalystcompounds excluding some convention-type chromium catalyst compounds areactivated with one or more of the conventional-type cocatalystsdescribed below.

[0032] Conventional-type Cocatalysts

[0033] Conventional-type cocatalyst compounds for the aboveconventional-type transition metal catalyst compounds may be representedby the formula M³M⁴ _(v)X² _(c)R³ _(b-c), wherein M³ is a metal fromGroup IA, IIA, IIB and IIIA of the Periodic Table of Elements; M⁴ is ametal of Group IA of the Periodic Table of Elements; v is a number from0 to 1; each X² is any halogen; c is a number from 0 to 3; each R³ is amonovalent hydrocarbon radical or hydrogen; b is a number from 1 to 4;and wherein b minus c is at least 1. Other conventional-typeorganometallic cocatalyst compounds for the above conventional-typetransition metal catalysts have the formula M³R³ _(k), where M³ is aGroup IA, IIA, IIB or IIIA metal, such as lithium, sodium, beryllium,barium, boron, aluminum, zinc, cadmium, and gallium; k equals 1, 2 or 3depending upon the valency of M³ which valency in turn normally dependsupon the particular Group to which M³ belongs; and each R³ may be anymonovalent hydrocarbon radical.

[0034] Non-limiting examples of conventional-type organometalliccocatalyst compounds of Group IA, IIA and IIIA useful with theconventional-type catalyst compounds described above includemethyllithium, butyllithium, dihexylmercury, butylmagnesium,diethylcadmium, benzylpotassium, diethylzinc, tri-n-butylaluminum,diisobutyl ethylboron, diethylcadmium, di-n-butylzinc andtri-n-amylboron, and, in particular, the aluminum alkyls, such astri-hexyl-aluminum, triethylaluminum, trimethylaluminum, andtri-isobutylaluminum. Other conventional-type cocatalyst compoundsinclude mono-organohalides and hydrides of Group IIA metals, and mono-or di-organohalides and. hydrides of Group IIIA metals. Non-limitingexamples of such conventional-type cocatalyst compounds includedi-isobutylaluminum bromide, isobutylboron dichloride, methyl magnesiumchloride, ethylberyllium chloride, ethylcalcium bromide,di-isobutylaluminum hydride, methylcadmium hydride, diethylboronhydride, hexylberyllium hydride, dipropylboron hydride, octylmagnesiumhydride, butylzinc hydride, dichloroboron hydride, di-bromo-aluminumhydride and bromocadmium hydride. Conventional-type organometalliccocatalyst compounds are known to those in the art and a more completediscussion of these compounds may be found in U.S. Pat. Nos. 3,221,002and 5,093,415, which are herein fully incorporated by reference.

[0035] For purposes of this patent specification and appended claimsconventional-type transition metal catalyst compounds exclude thosebulky ligand metallocene-type catalyst compounds discussed below. Forpurposes of this patent specification and the appended claims the term“cocatalyst” refers to conventional-type cocatalysts orconventional-type organometallic cocatalyst compounds. Bulky ligandmetallocene-type catalyst compounds and catalyst systems for use incombination with a carboxylate metal salt of the invention are describedbelow.

[0036] Bulky Ligand Metallocene-type Catalyst Compounds

[0037] Generally, bulky ligand metallocene-type catalyst compoundsinclude half and full sandwich compounds having one or more bulkyligands including cyclopentadienyl-type structures or other similarfunctioning structure such as pentadiene, cyclooctatetraendiyl andimides. Typical bulky ligand metallocene-type compounds are generallydescribed as containing one or more ligands capable of η-5 bonding to atransition metal atom, usually, cyclopentadienyl derived ligands ormoieties, in combination with a transition metal selected from Group 3to 8, preferably 4, 5 or 6 or from the lanthanide and actinide series ofthe Periodic Table of Elements. Exemplary of these bulky ligandmetallocene-type catalyst compounds and catalyst systems are describedin for example, U.S. Pat. Nos. 4,530,914, 4,871,705, 4,937,299,5,017,714, 5,055,438, 5,096, 867, 5,120,867, 5,124,418, 5,198,401,5,210,352, 5,229,478, 5,264,405, 5,278,264, 5,278,119, 5,304,614,5,324,800, 5,347,025, 5,350,723, 5,384,299, 5,391,790, 5,391,789,5,399,636, 5,408,017, 5,491,207, 5,455,366, 5,534,473, 5,539,124,5,554,775, 5,621,126, 5,684,098, 5,693,730, 5,698,634, 5,710,297,5,712,354, 5,714,427, 5,714,555, 5,728,641, 5,728,839, 5,753,577,5,767,209, 5,770,753 and 5,770,664 all of which are herein fullyincorporated by reference. Also, the disclosures of Europeanpublications EP-A-0 591 756, EP-A-0 520 732, EP-A-0 420 436, EP-B1 0 485822, EP-B1 0 485 823, EP-A2-0 743 324 and EP-B1 0 518 092 and PCTpublications WO 91/04257, WO 92/00333, WO 93/08221, WO 93/08199, WO94/01471, WO 96/20233, WO 97/15582, WO 97/19959, WO 97/46567, WO98/01455, WO 98/06759 and WO 98/011144 are all herein fully incorporatedby reference for purposes of describing typical bulky ligandmetallocene-type catalyst compounds and catalyst systems.

[0038] In one embodiment, bulky ligand metallocene-type catalystcompounds of the invention are represented by the formula:

L^(A)L^(B)MQ  (I)

[0039] where M is a metal from the Periodic Table of the Elements andmay be a Group 3 to 10 metal, preferably, a Group 4, 5 or 6 transitionmetal or a metal from the lanthanide or actinide series, more preferablyM is a transition metal from Group 4, even more preferably zirconium,hafinium or titanium. L^(A) and L^(B) are bulky ligands that includecyclopentadienyl derived ligands or substituted cyclopentadienyl derivedligands or heteroatom substituted or heteroatom containingcyclopentadienyl derived ligands, or hydrocarbyl substitutedcyclopentadienyl derived ligands, or moieties such as indenyl ligands,benzindenyl ligands, fluorenyl ligands, octahydrofluorenyl ligands,cyclooctatetraendiyl ligands, azenyl ligands and borabenzene ligands,and the like, including hydrogenated versions thereof. Also, L^(A) andL^(B) may be any other ligand structure capable of η-5 bonding to M, forexample L^(A) and L^(B) may comprises one or more heteroatoms, forexample, nitrogen, silicon, boron, germanium, and phosphorous, incombination with carbon atoms to form a cyclic structure, for example aheterocyclopentadienyl ancillary ligand. Further, each of L^(A) andL^(B) may also be other types of bulky ligands including but not limitedto bulky amides, phosphides, alkoxides, aryloxides, imides, carbolides,borollides, porphyrins, phthalocyanines, corrins and otherpolyazomacrocycles. Each L^(A) and L^(B) may be the same or differenttype of bulky ligand that is π-bonded to M.

[0040] Each L^(A) and L^(B) may be substituted with a combination ofsubstituent groups R. Non-limiting examples of substituent groups Rinclude hydrogen or linear, branched, alkyl radicals or cyclic alkyl,alkenyl, alkynl or aryl radicals or combination thereof having from 1 to30 carbon atoms or other substituents having up to 50 non-hydrogen atomsthat can also be substituted. Non-limiting examples of alkylsubstituents R include methyl, ethyl, propyl, butyl, pentyl, hexyl,cyclopentyl, cyclohexyl, benzyl or phenyl groups, halogens and the like,including all their isomers, for example tertiary butyl, iso-propyl,etc. Other hydrocarbyl radicals include fluoromethyl, fluroethyl,difluroethyl, iodopropyl, bromohexyl, chlorobenzyl and hydrocarbylsubstituted organometalloid radicals including trimethylsilyl,trimethylgermyl, methyldiethylsilyl and the like; andhalocarbyl-substituted organometalloid radicals includingtris(trifluoromethyl)-silyl, methyl-bis (difluoromethyl)silyl,bromomethyldimethylgermyl and the like; and disubstitiuted boronradicals including dimethylboron for example; and disubstitutedpnictogen radicals including dimethylamine, dimethylphosphine,diphenylamine, methylphenylphosphine, chalcogen radicals includingmethoxy, ethoxy, propoxy, phenoxy, methylsulfide and ethylsulfide.Non-hydrogen substituents R include the atoms carbon, silicon, nitrogen,phosphorous, oxygen, tin, germanium and the like including olefins suchas but not limited to olefinically unsaturated substituents includingvinyl-terminated ligands, for example but-3-enyl, 2-vinyl, or hexene-l.Also, at least two R groups, preferably two adjacent R groups are joinedto form a ring structure having from 4 to 30 atoms selected from carbon,nitrogen, oxygen, phosphorous, silicon, germanium, boron or acombination thereof. Also, an R group such as 1-butanyl may form acarbon sigma bond to the metal M.

[0041] Other ligands may be bonded to the transition metal, such as aleaving group Q. Q may be independently monoanionic labile ligandshaving a sigma-bond to M. Non-limiting examples of Q include weak basessuch as amines, phosphines, ether, carboxylates, dienes, hydrocarbylradicals having from 1 to 20 carbon atoms, hydrides or halogens and thelike, and combinations thereof. Other examples of Q radicals includethose substituents for R as described above and including cyclohexyl,heptyl, tolyl, trifluromethyl, tetramethylene and pentamethylene,methylidene, methyoxy, ethyoxy, propoxy, phenoxy, bis(N-methylanilide),dimethylamide, dimethylphosphide radicals and the like.

[0042] In addition, bulky ligand metallocene-type catalyst compounds ofthe invention are those where L^(A) and L^(B) are bridged to each otherby a bridging group, A. These bridged compounds are known as bridged,bulky ligand metallocene-type catalyst compounds. Non-limiting examplesof bridging group A include bridging radicals of at least one Group 14atom, such as but not limited to carbon, oxygen, nitrogen, silicon,germanium and tin, preferably carbon, silicon and germanium, mostpreferably silicon. Other non-limiting examples of bridging groups Ainclude dimethylsilyl, diethylsilyl, methylethylsilyl,trifluoromethylbutylsilyl, bis(trifluoromethyl)silyl, di-n-butylsilyl,silylcyclobutyl, di-i-propylsilyl, di-cyclohexylsilyl, di-phenylsilyl,cyclohexylphenylsilyl, t-butylcyclohexylsilyl, di-t-butylphenylsilyl,di(p-tolyl)silyl, dimethylgermyl, diethylgermyl, methylene,dimethylmethylene, diphenylmethylene, ethylene, 1-2-dimethylethylene,1,2-diphenylethylene, 1,1,2,2-tetramethylethylene,dimethylmethylenedimethylsilyl, methylenediphenylgermyl, methylamine,phenylamine, cyclohexylamine, methylphosphine, phenylphosphine,cyclohexylphosphine and the like.

[0043] In another embodiment, the bulky ligand metallocene-type catalystcompound of the invention is represented by the formula:

(C₅H_(4-d)R_(d))A_(x)(C₅H_(4-d)R_(d))M Qg-₂  (II)

[0044] wherein M is a Group 4, 5 , 6 transition metal, (C₅H_(4-d)R_(d))is an unsubstituted or substituted cyclopentadienyl derived bulky ligandbonded to M, each R, which can be the same or different, is hydrogen ora substituent group containing up to 50 non-hydrogen atoms orsubstituted or unsubstituted hydrocarbyl having from 1 to 30 carbonatoms or combinations thereof, or two or more carbon atoms are joinedtogether to form a part of a substituted or unsubstituted ring or ringsystem having 4 to 30 carbon atoms, A is one or more of, or acombination of carbon, germanium, silicon, tin, phosphorous or nitrogenatom containing radical bridging two (C₅H_(4-d)R_(d)) rings; moreparticularly, non-limiting examples of A may be represented by R′₂C,R′₂Si, R′₂Si R′₂Si, R′₂Si R′₂C, R′₂Ge, R′₂Ge, R′₂Si R′₂Ge, R′₂GeR′₂C,R′N, R′P, R′₂C R′N, R′₂C R′P, R′₂Si R′N, R′₂Si R′P, R′₂GeR′N, R′₂Ge R′P,where R′ is independently, a radical group which is hydride, C₁₋₃₀hydrocarbyl, substituted hydrocarbyl, halocarbyl, substitutedhalocarbyl, hydrocarbyl-substituted organometalloid,halocarbyl-substituted organometalloid, disubstituted boron,disubstituted pnictogen, substituted chalcogen, or halogen; each Q whichcan be the same or different is a hydride, substituted or unsubstituted,linear, cyclic or branched, hydrocarbyl having from 1 to 30 carbonatoms, halogen, alkoxides, aryloxides, amides, phosphides, or any otherunivalent anionic ligand or combination thereof; also, two Q's togethermay form an alkylidene ligand or cyclometallated hydrocarbyl ligand orother divalent anionic chelating ligand, where g is an integercorresponding to the formal oxidation state of M, and d is an integerselected from the 0, 1, 2, 3 or 4 and denoting the degree ofsubstitution and x is an integer from 0 to 1.

[0045] In one embodiment, the bulky ligand metallocene-type catalystcompounds are those where the R substituents on the bulky ligands L^(A),L^(B), (C₅H_(4-d)R_(d)) of formulas (I) and (II) are substituted withthe same or different number of substituents on each of the bulkyligands.

[0046] In a preferred embodiment, the bulky ligand metallocene-typecatalyst is represented by formula (II), where x is 1.

[0047] Other bulky ligand metallocene-type catalysts compounds useful inthe invention include bridged, mono-bulky ligand heteroatom containingmetallocene-type compounds. These types of catalysts and catalystsystems are described in, for example, PCT publication WO 92/00333, WO94/07928, WO 91/04257, WO 94/03506, WO 96/00244 and WO 97/15602 and U.S.Pat. Nos. 5,057,475, 5,096,867, 5,055,438, 5,198,401, 5,227,440 and5,264,405 and European publication EP-A-0 420 436, all of which areherein fully incorporated by reference. Other bulky ligandmetallocene-type catalysts useful in the invention may include thosedescribed in U.S. Pat. Nos. 5,064,802, 5,145,819, 5,149,819, 5,243,001,5,239,022, 5,276,208, 5,296,434, 5,321,106, 5,329,031, 5,304,614,5,677,401 and 5,723,398 and PCT publications WO 93/08221, WO 93/08199,WO 95/07140, WO 98/11144 and European publications EP-A-0 578 838,EP-A-0 638 595, EP-B-0 513 380 and EP-A1-0 816 372, all of which areherein fully incorporated by reference.

[0048] In another embodiment of this invention the bridged, mono-bulkyligand heteroatom containing metallocene-type catalyst compounds usefulin the invention are represented by the formula:

[0049] wherein M is Ti, Zr or Hf; (C₅H_(5-y-x)R_(x)) is acyclopentadienyl ring or ring system which is substituted with from 0 to5 substituent groups R, “x” is 0, 1, 2, 3, 4 or 5 denoting the degree ofsubstitution, and each substituent group R is, independently, a radicalselected from a group consisting of C₁-C₂₀ hydrocarbyl radicals,substituted C₁-C₂₀ hydrocarbyl radicals wherein one or more hydrogenatoms is replaced by a halogen atom, C₁-C₂₀ hydrocarbyl-substitutedmetalloid radicals wherein the metalloid is selected from the Group 14of the Periodic Table of Elements, and halogen radicals or(C₅H_(5-y-x)R_(x)) is a cyclopentadienyl ring in which two adjacentR-groups are joined forming C₄-C₂₀ ring to give a saturated orunsaturated polycyclic cyclopentadienyl ligand such as indenyl,tetrahydroindenyl, fluorenyl or octahydrofluorenyl;

[0050] (JR′_(z-1-y)) is a heteroatom ligand in which J is an elementwith a coordination number of three from Group 15 or an element with acoordination number of two from Group 16 of the Periodic Table ofElements, preferably nitrogen, phosphorus, oxygen or sulfur withnitrogen being preferred, and each R′ is, independently a radicalselected from a group consisting of C₁-C₂₀ hydrocarbyl radicals whereinone or more hydrogen atoms is replaced by a halogen atom, y is 0 or 1,and “z” is the coordination number of the element J;

[0051] each Q is, independently any univalent anionic ligand such ashalogen, hydride, or substituted or unsubstituted C₁-C₃₀ hydrocarbyl,alkoxide, aryloxide, amide or phosphide, provided that two Q may be analkylidene, a cyclometallated hydrocarbyl or any other divalent anionicchelating ligand; and n may be 0,1 or 2;

[0052] A is a covalent bridging group containing a Group 15 or 14element such as, but not limited to, a dialkyl, alkylaryl or diarylsilicon or germanium radical, alkyl or aryl phosphine or amine radical,or a hydrocarbyl radical such as methylene, ethylene and the like;

[0053] L′ is a Lewis base such as diethylether, tetraethylammoniumchloride, tetrahydrofuran, dimethylaniline, aniline, trimethylphosphine,n-butylamine, and the like; and w is a number from 0 to 3. Additionally,L′ may be bonded to any of R, R′ or Q and n is 0, 1, 2 or 3.

[0054] In another embodiment, the bulky ligand type metallocene-typecatalyst compound is a complex of a transition metal, a substituted orunsubstituted pi-bonded ligand, and one or more heteroallyl moieties,such as those described in U.S. Pat. Nos. 5,527,752 and 5,747,406 andEP-B1-0 735 057, all of which are herein fully incorporated byreference. Preferably, the bulky ligand type metallocene-type catalystcompound, the monocycloalkadienyl catalyst compound, may be representedby one of the following formulas:

[0055] wherein M is a transition metal from Group 4, 5 or 6, preferablytitanium zirconium or hafnium, most preferably zirconium or hafnium; Lis a substituted or unsubstituted, pi-bonded ligand coordinated to M,preferably L is a cycloalkadienyl bulky ligand, for examplecyclopentadienyl, indenyl or fluorenyl bulky ligands, optionally withone or more hydrocarbyl substituent groups having from 1 to 20 carbonatoms; each Q is independently selected from the group consisting of—O—, —NR—, —CR₂— and —S—, preferably oxygen; Y is either C or S,preferably carbon; Z is selected from the group consisting of —OR, —NR₂,—CR₃, —SR, —SiR₃, —PR₂, —H, and substituted or unsubstituted arylgroups, with the proviso that when Q is —NR— then Z is selected from thegroup consisting of —OR, —NR₂, —SR, —SiR₃, —PR₂ and —H, preferably Z isselected from the group consisting of —OR, —CR₃ and —NR₂; n is 1 or 2,preferably 1; A is a univalent anionic group when n is 2 or A is adivalent anionic group when n is 1, preferably A is a carbamate,carboxylate, or other heteroallyl moiety described by the Q, Y and Zcombination; and each R is independently a group containing carbon,silicon, nitrogen, oxygen, and/or phosphorus where one or more R groupsmay be attached to the L substituent, preferably R is a hydrocarbongroup containing from 1 to 20 carbon atoms, most preferably an alkyl,cycloalkyl, or an aryl group and one or more may be attached to the Lsubstituent; and T is a bridging group selected from the groupconsisting of alkylene and arylene groups containing from 1 to 10 carbonatoms optionally substituted with carbon or heteroatom(s), germanium,silicon and alkyl phosphine; and m is 2 to 7, preferably 2 to 6, mostpreferably 2 or 3.

[0056] In formulas (IV) and (V), the supportive substituent formed by Q,Y and Z is a unicharged polydentate ligand exerting electronic effectsdue to its high polarizability, similar to the cyclopentadienyl ligand.In the most preferred embodiments of this invention, the disubstitutedcarbamates and the carboxylates are employed. Non-limiting examples ofthese bulky ligand metallocene-type catalyst compounds include indenylzirconium tris(diethylcarbamate), indenyl zirconiumtris(trimethylacetate), indenyl zirconium tris(p-toluate), indenylzirconium tris(benzoate), (1-methylindenyl)zirconiumtris(trimethylacetate), (2-methylindenyl) zirconiumtris(diethylcarbamate), (methylcyclopentadienyl) zirconiumtris(trimethylacetate), cyclopentadienyl tris(trimethylacetate),tetrahydroindenyl zirconium tris(trimethylacetate), and(pentamethyl-cyclopentadienyl) zirconium tris(benzoate). Preferredexamples are indenyl zirconium tris(diethylcarbamate), indenyl zirconiumtris(trimethylacetate), and (methylcyclopentadienyl) zirconiumtris(trimethylacetate).

[0057] In another embodiment of the invention the bulky ligandmetallocene-type catalyst compounds are those nitrogen containingheterocyclic ligand complexes, also known as transition metal catalystsbased on bidentate ligands containing pyridine or quinoline moieties,such as those described in WO 96/33202, WO 99/01481 and WO 98/42664 andU.S. Pat. No. 5,637,660, which are herein all incorporated by reference.

[0058] It is within the scope of this invention, in one embodiment, thatbulky ligand metallocene-type catalyst compound complexes of Ni²⁺andPd²⁺described in the articles Johnson, et al., “New Pd(II)- andNi(II)-Based Catalysts for Polymerization of Ethylene and a-Olefms”, J.Am. Chem. Soc. 1995, 117, 6414-6415 and Johnson, et al.,“Copolymerization of Ethylene and Propylene with Functionalized VinylMonomers by Palladium(II) Catalysts”, J. Am. Chem. Soc., 1996, 118,267-268, and WO 96/23010 published Aug. 1, 1996, which are all hereinfully incorporated by reference, may be combined with a carboxylatemetal salt for use in the process of invention. These complexes can beeither dialkyl ether adducts, or alkylated reaction products of thedescribed dihalide complexes that can be activated to a cationic stateby the conventional-type cocatalysts or the activators of this inventiondescribed below.

[0059] Also included as bulky ligand metallocene-type catalyst compoundsare those diimine based ligands for Group 8 to 10 metal compoundsdisclosed in PCT publications WO 96/23010 and WO 97/48735 and Gibson,et. al., Chem. Comm., pp. 849-850 (1998), all of which are hereinincorporated by reference.

[0060] Other bulky ligand metallocene-type catalysts are those Group 5and 6 metal imido complexes described in EP-A2-0 816 384 and U.S. Pat.No. 5,851,945, which is incorporated herein by reference. In addition,bulky ligand metallocene-type catalysts include bridged bis(arylamido)Group 4 compounds described by D. H. McConville, et al., inOrganometallics 1195, 14, 5478-5480, which is herein incorporated byreference. Other bulky ligand metallocene-type catalysts are describedas bis(hydroxy aromatic nitrogen ligands) in U.S. Pat. No. 5,852,146,which is incorporated herein by reference. Other metallocene-typecatalysts containing one or more Group 15 atoms include those describedin WO 98/46651, which is herein incorporated herein by reference. Stillanother metallocene-type bulky ligand metallocene-type catalysts includethose multinuclear bulky ligand metallocene-type catalysts as describedin WO 99/20665, which is incorporated herein by reference.

[0061] It is contemplated in some embodiments, that the bulky ligands ofthe metallocene-type catalyst compounds of the invention described abovemay be asymmetrically substituted in terms of additional substituents ortypes of substituents, and/or unbalanced in terms of the number ofadditional substituents on the bulky ligands or the bulky ligandsthemselves are different.

[0062] It is also contemplated that in one embodiment, the bulky ligandmetallocene-type catalysts of the invention include their structural oroptical or enantiomeric isomers (meso and racemic isomers) and mixturesthereof. In another embodiment the bulky ligand metallocene-typecompounds of the invention may be chiral and/or a bridged bulky ligandmetallocene-type catalyst compound.

[0063] Activator and Activation Methods For the Bulky LigandMetallocene-type Catalyst Compounds

[0064] The above described bulky ligand metallocene-type catalystcompounds of the invention are typically activated in various ways toyield catalyst compounds having a vacant coordination site that willcoordinate, insert, and polymerize olefin(s).

[0065] For the purposes of this patent specification and appendedclaims, the term “activator” is defined to be any compound or componentor method which can activate any of the bulky ligand metallocene-typecatalyst compounds of the invention as described above. Non-limitingactivators, for example may include a Lewis acid or a non-coordinatingionic activator or ionizing activator or any other compounds includingLewis bases, aluminum alkyls, conventional-type cocatalysts (previouslydescribed herein) and combinations thereof that can convert a neutralbulky ligand metallocene-type catalyst compound to a catalyticallyactive bulky ligand metallocene-type cation. It is within the scope ofthis invention to use alumoxane or modified alumoxane as an activator,and/or to also use ionizing activators, neutral or ionic, such as tri(n-butyl) ammonium tetrakis (pentafluorophenyl) boron, atrisperfluorophenyl boron metalloid precursor or a trisperfluoronaphtylboron metalloid precursor, polyhalogenated heteroborane anions (WO98/43983) or combination thereof, that would ionize the neutral bulkyligand metallocene-type catalyst compound.

[0066] In one embodiment, an activation method using ionizing ioniccompounds not containing an active proton but capable of producing botha bulky ligand metallocene-type catalyst cation and a noncoordinatinganion are also contemplated, and are described in EP-A-0 426 637, EP-A-0573 403 and U.S. Pat. No. 5,387,568, which are all herein incorporatedby reference.

[0067] There are a variety of methods for preparing alumoxane andmodified alumoxanes, non-limiting examples of which are described inU.S. Pat. Nos. 4,665,208, 4,952,540, 5,091,352, 5,206,199, 5,204,419,4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,308,815, 5,329,032,5,248,801, 5,235,081, 5,157,137, 5,103,031, 5,391,793, 5,391,529,5,693,838, 5,731,253, 5,731,451 5,744,656 and European publicationsEP-A-0 561 476, EP-B 1-0 279 586 and EP-A-0 594-218, and PCT publicationWO 94/10180, all of which are herein fully incorporated by reference.

[0068] Ionizing compounds may contain an active proton, or some othercation associated with but not coordinated to or only looselycoordinated to the remaining ion of the ionizing compound. Suchcompounds and the like are described in European publications EP-A-0 570982, EP-A-0 520 732, EP-A-0 495 375, EP-A-500 944, EP-A-0 277 003 andEP-A-0 277 004, and U.S. Pat. Nos. 5,153,157, 5,198,401, 5,066,741,5,206,197, 5,241,025, 5,384,299 and 5,502,124 and U.S. patentapplication Ser. No. 08/285,380, filed Aug. 3, 1994, all of which areherein fully incorporated by reference.

[0069] Other activators include those described in PCT publication WO98/07515 such as tris (2, 2′, 2″-nonafluorobiphenyl) fluoroaluminate,which publication is fully incorporated herein by reference.Combinations of activators are also contemplated by the invention, forexample, alumoxanes and ionizing activators in combinations, see forexample, EP-B1 0 573 120, PCT publications WO 94/07928 and WO 95/14044and U.S. Pat. Nos. 5,153,157 and 5,453,410 all of which are herein fullyincorporated by reference. WO 98/09996 incorporated herein by referencedescribes activating bulky ligand metallocene-type catalyst compoundswith perchlorates, periodates and iodates including their hydrates. WO98/30602 and WO 98/30603 incorporated by reference describe the use oflithium (2,2′-bisphenyl-ditrimethylsilicate).4THF as an activator for abulky ligand metallocene-type catalyst compound. WO 99/18135incorporated herein by reference describes the use oforgano-boron-aluminum activators. EP-B1-0 781 299 describes using asilylium salt in combination with a non-coordinating compatible anion.Also, methods of activation such as using radiation (see EP-B 1-0 615981 herein incorporated by reference), electro-chemical oxidation, andthe like are also contemplated as activating methods for the purposes ofrendering the neutral bulky ligand metallocene-type catalyst compound orprecursor to a bulky ligand metallocene-type cation capable ofpolymerizing olefins. Other activators or methods for activating a bulkyligand metallocene-type catalyst compound are described in for example,U.S. Pat. Nos. 5,849,852, 5,859,653 and 5,869,723 and PCT WO 98/32775,which are herein incorporated by reference.

[0070] Mixed Catalysts

[0071] It is also within the scope of this invention that the abovedescribed bulky ligand metallocene-type catalyst compounds can becombined with one or more of the catalyst compounds represented byformula (I), (II), (III), (IV) and (V) with one or more activators oractivation methods described above.

[0072] It is further contemplated by the invention that other catalystscan be combined with the bulky ligand metallocene-type catalystcompounds of the invention. For example, see U.S. Pat. Nos. 4,937,299,4,935,474, 5,281,679, 5,359,015, 5,470,811, and 5,719,241 all of whichare herein fully incorporated herein reference.

[0073] In another embodiment of the invention one or more bulky ligandmetallocene-type catalyst compounds or catalyst systems may be used incombination with one or more conventional-type catalyst compounds orcatalyst systems. Non-limiting examples of mixed catalysts and catalystsystems are described in U.S. Pat. Nos. 4,159,965, 4,325,837, 4,701,432,5,124,418, 5,077,255, 5,183,867, 5,391,660, 5,395,810, 5,691,264,5,723,399 and 5,767,031 and PCT Publication WO 96/23010 published Aug.1, 1996, all of which are herein fully incorporated by reference.

[0074] It is further contemplated that two or more conventional-typetransition metal catalysts may be combined with one or moreconventional-type cocatalysts. Non-limiting examples of mixedconventional-type transition metal catalysts are described in forexample U.S. Pat. Nos. 4,154,701, 4,210,559, 4,263,422, 4,672,096,4,918,038, 5,198,400, 5,237,025, 5,408,015 and 5,420,090, all of whichare herein incorporated by reference.

[0075] Method for Supporting

[0076] The above described bulky ligand metallocene-type catalystcompounds and catalyst systems and conventional-type transition metalcatalyst compounds and catalyst systems may be combined with one or moresupport materials or carriers using one of the support methods wellknown in the art or as described below. In the preferred embodiment, themethod of the invention uses a polymerization catalyst in a supportedform. For example, in a most preferred embodiment, a bulky ligandmetallocene-type catalyst compound or catalyst system is in a supportedform, for example deposited on, contacted with, or incorporated within,adsorbed or absorbed in a support or carrier.

[0077] The terms “support” or “carrier” are used interchangeably and areany porous or non-porous support material, preferably a porous supportmaterial, for example, talc, inorganic oxides and inorganic chlorides.Other carriers include resinous support materials such as polystyrene, afunctionalized or crosslinked organic supports, such as polystyrenedivinyl benzene polyolefins or polymeric compounds, or any other organicor inorganic support material and the like, or mixtures thereof.

[0078] The preferred carriers are inorganic oxides that include thoseGroup 2, 3, 4, 5, 13 or 14 metal oxides. The preferred supports includessilica, alumina, silica-alumina, magnesium chloride, and mixturesthereof. Other useful supports include magnesia, titania, zirconia,montmorillonite and the like. Also, combinations of these supportmaterials may be used, for example, silica-chromium and silica-titania.

[0079] It is preferred that the carrier, most preferably an inorganicoxide, has a surface area in the range of from about 10 to about 700m²/g, pore volume in the range of from about 0.1 to about 4.0 cc/g andaverage particle size in the range of from about 10 to about 500 μm.More preferably, the surface area of the carrier is in the range of fromabout 50 to about 500 m²/g, pore volume of from about 0.5 to about 3.5cc/g and average particle size of from about 20 to about 200 μm. Mostpreferably the surface area of the carrier is in the range of from about100 to about 400 m²/g, pore volume from about 0.8 to about 3.0 cc/g andaverage particle size is from about 20 to about 100 μm. The average poresize of a carrier of the invention is typically in the range of fromabout 10 Å to 1000 Å, preferably 50 Å to about 500 Å, and mostpreferably 75 Å to about 350 Å.

[0080] Examples of supporting the bulky ligand metallocene-type catalystsystems of the invention are described in U.S. Pat. Nos. 4,701,432,4,808,561, 4,912,075, 4,925,821, 4,937,217, 5,008,228, 5,238,892,5,240,894, 5,332,706, 5,346,925, 5,422,325, 5,466,649, 5,466,766,5,468,702, 5,529,965, 5,554,704, 5,629,253, 5,639,835, 5,625,015,5,643,847, 5,665,665, 5,698,487, 5,714,424, 5,723,400, 5,723,402,5,731,261, 5,759,940, 5,767,032 and 5,770,664 and U.S. application Ser.Nos. 271,598 filed Jul. 7, 1994 and 788,736 filed Jan. 23, 1997 and PCTpublications WO 95/32995, WO 95/14044, WO 96/06187 and WO 97/02297 allof which are herein fully incorporated by reference.

[0081] Examples of supporting the conventional-type catalyst systems ofthe invention are described in U.S. Pat. Nos. 4,894,424, 4,376,062,4,395,359, 4,379,759, 4,405,495 4,540758 and 5,096,869, all of which areherein incorporated by reference.

[0082] It is contemplated that the bulky ligand metallocene-typecatalyst compounds of the invention may be deposited on the same orseparate supports together with an activator, or the activator may beused in an unsupported form, or may be deposited on a support differentfrom the supported bulky ligand metallocene-type catalyst compounds ofthe invention, or any combination thereof.

[0083] There are various other methods in the art for supporting apolymerization catalyst compound or catalyst system of the invention.For example, the bulky ligand metallocene-type catalyst compound of theinvention may contain a polymer bound ligand as described in U.S. Pat.Nos. 5,473,202 and 5,770,755, which is herein fully incorporated byreference; the bulky ligand metallocene-type catalyst system of theinvention may be spray dried as described in U.S. Pat. No. 5,648,310,which is herein fully incorporated by reference; the support used withthe bulky ligand metallocene-type catalyst system of the invention isfunctionalized as described in European publication EP-A-0 802 203,which is herein fully incorporated by reference; or at least onesubstituent or leaving group is selected as described in U.S. Pat. No.5,688,880, which is herein fully incorporated by reference.

[0084] In a preferred embodiment, the invention provides for a supportedbulky ligand metallocene-type catalyst system that includes a surfacemodifier that is used in the preparation of the supported catalystsystem, as described in PCT publication WO 96/11960 which is hereinfully incorporated by reference.

[0085] A preferred method for producing the supported bulky ligandmetallocene-type catalyst system of the invention is described below andcan be found in U.S. application Ser. Nos. 265,533, filed Jun. 24, 1994and 265,532, filed Jun. 24, 1994 and PCT publications WO 96/00245 and WO96/00243 both published Jan. 4, 1996, all of which are herein fullyincorporated by reference. In this preferred method, the bulky ligandmetallocene-type catalyst compound is slurried in a liquid to form ametallocene solution and a separate solution is formed containing anactivator and a liquid. The liquid may be any compatible solvent orother liquid capable of forming a solution or the like with the bulkyligand metallocene-type catalyst compounds and/or activator of theinvention. In the most preferred embodiment the liquid is a cyclicaliphatic or aromatic hydrocarbon, most preferably toluene. The bulkyligand metallocene-type catalyst compound and activator solutions aremixed together and added to a porous support or the porous support isadded to the solutions such that the total volume of the bulky ligandmetallocene-type catalyst compound solution and the activator solutionor the bulky ligand metallocene-type catalyst compound and activatorsolution is less than five times the pore volume of the porous support,more preferably less than four times, even more preferably less thanthree times; preferred ranges being from 1.1 times to 3.5 times rangeand most preferably in the 1.2 to 3 times range.

[0086] Procedures for measuring the total pore volume of a poroussupport are well known in the art. Details of one of these procedures isdiscussed in Volume 1, Experimental Methods in Catalytic Research(Academic Press, 1968) (specifically see pages 67-96). This preferredprocedure involves the use of a classical BET apparatus for nitrogenabsorption. Another method well known in the art is described in Innes,Total Porosity and Particle Density of Fluid Catalysts By LiquidTitration, Vol. 28, No. 3, Analytical Chemistry 332-334 (March, 1956).

[0087] The mole ratio of the metal of the activator component to themetal of the bulky ligand metallocene-type catalyst compounds are in therange of between 0.3:1 to 2000:1, preferably 20:1 to 800:1, and mostpreferably 50:1 to 500:1. Where the activator is an ionizing activatorsuch as those based on the anion tetrakis(pentafluorophenyl)boron, themole ratio of the metal of the activator component to the metalcomponent of the catalyst is preferably in the range of between 0.3:1 to3:1.

[0088] In one embodiment of the invention, olefin(s), preferably C₂ toC₃₀ olefin(s) or alpha-olefin(s), preferably ethylene or propylene orcombinations thereof are prepolymerized in the presence of the bulkyligand metallocene-type catalyst system and/or a conventional-typetransition metal catalysts of the invention prior to the mainpolymerization. The prepolymerization can be carried out batchwise orcontinuously in gas, solution or slurry phase including at elevatedpressures. The prepolymerization can take place with any olefin monomeror combination and/or in the presence of any molecular weightcontrolling agent such as hydrogen. For examples of prepolymerizationprocedures, see U.S. Pat. Nos. 4,748,221, 4,789,359, 4,923,833,4,921,825, 5,283,278 and 5,705,578 and European publication EP-B-0279863 and PCT Publication WO 97/44371 all of which are herein fullyincorporated by reference. A prepolymerized catalyst system for purposesof this patent specification and appended claim is a supported catalystsystem.

[0089] Carboxylate Metal Salt

[0090] Carboxylate metal salts are well known in the art as additivesfor use with polyolefins, for example as a film processing aid. Thesetypes of post reactor processing additives are commonly used asemulsifying agents, antistat and antifogging agents, stabilizers,foaming aids, lubrication aids, mold release agents, nucleating agents,and slip and antiblock agents and the like. Thus, it was trulyunexpected that these post reactor agents or aids would be useful with apolymerization catalyst to improve the operability of a polymerizationprocess.

[0091] For the purposes of this patent specification and appended claimsthe term “carboxylate metal salt” is any mono- or di- or tri-carboxylicacid salt with a metal portion from the Periodic Table of Elements.Non-limiting examples include saturated, unsaturated, aliphatic,aromatic or saturated cyclic carboxylic acid salts where the carboxylateligand has preferably from 2 to 24 carbon atoms, such as acetate,propionate, butyrate, valerate, pivalate, caproate, isobuytlacetate,t-butyl-acetate, caprylate, heptanate, pelargonate, undecanoate, oleate,octoate, palmitate, myristate, margarate, stearate, arachate andtercosanoate. Non-limiting examples of the metal portion includes ametal from the Periodic Table of Elements selected from the group of Al,Mg, Ca, Sr, Sn, Ti, V, Ba, Zn, Cd, Hg, Mn, Fe, Co, Ni, Pd, Li and Na.

[0092] In one embodiment, the carboxylate metal salt is represented bythe following general formula:

M(Q)_(X)(OOCR)_(Y)

[0093] where M is a metal from Groups 1 to 16 and the Lanthanide andActinide series, preferably from Groups 1 to 7 and 13 to 16, morepreferably from Groups 3 to 7 and 13 to 16, even more preferably Groups2 and 13, and most preferably Group 13; Q is halogen, hydrogen, ahydroxy or hydroxide, alkyl, alkoxy, aryloxy, siloxy, silane sulfonategroup or siloxane; R is a hydrocarbyl radical having from 2 to 100carbon atoms, preferably 4 to 50 carbon atoms; and x is an integer from0 to 3 and y is an integer from 1 to 4 and the sum of x and y is equalto the valence of the metal. In a preferred embodiment of the aboveformula y is an integer from 1 to 3, preferably 1 to 2, especially whereM is a Group 13 metal.

[0094] Non-limiting examples of R in the above formula includehydrocarbyl radicals having 2 to 100 carbon atoms that include alkyl,aryl, aromatic, aliphatic, cyclic, saturated or unsaturated hydrocarbylradicals. In an embodiment of the invention, R is a hydrocarbyl radicalhaving greater than or equal to 8 carbon atoms, preferably greater thanor equal to 12 carbon atoms and more preferably greater than or equal to17 carbon atoms. In another embodiment R is a hydrocarbyl radical havingfrom 17 to 90 carbon atoms, preferably 17 to 72, and most preferablyfrom 17 to 54 carbon atoms.

[0095] Non-limiting examples of Q in the above formula include one ormore, same or different, hydrocarbon containing group such as alkyl,cycloalkyl, aryl, alkenyl, arylalkyl, arylalkenyl or alkylaryl,alkylsilane, arylsilane, alkylamine, arylamine, alkyl phosphide, alkoxyhaving from 1 to 30 carbon atoms. The hydrocarbon containing group maybe linear, branched, or even substituted. Also, Q in one embodiment isan inorganic group such as a halide, sulfate or phosphate.

[0096] In one embodiment, the more preferred carboxylate metal salts arethose aluminum carboxylates such as aluminum mono, di- andtri-stearates, aluminum octoates, oleates and cyclohexylbutyrates. Inyet a more preferred embodiment, the carboxylate metal salt is(CH₃(CH₂)₁₆COO)₃Al, a aluminum tri-stearate (preferred melting point115° C.), (CH₃(CH₂)₁₆COO)₂—Al—OH, a aluminum di-stearate (preferredmelting point 145° C.), and a CH₃(CH₂)₁₆COO—Al(OH)₂, an aluminummono-stearate (preferred melting point 155° C.).

[0097] Non-limiting commercially available carboxylate metal salts forexample include Witco Aluminum Stearate # 18, Witco Aluminum Stearate #22, Witco Aluminum Stearate # 132 and Witco Aluminum Stearate EA FoodGrade, all of which are available from Witco Corporation, Memphis, Tenn.

[0098] In one embodiment the carboxylate metal salt has a melting pointfrom about 30° C. to about 250° C., more preferably from about 37° C. toabout 220° C., even more preferably from about 50° C. to about 200° C.,and most preferably from about 100° C. to about 200° C. In a mostpreferred embodiment, the carboxylate metal salt is an aluminum stearatehaving a melting point in the range of from about 135° C. to about 165°C.

[0099] In another preferred embodiment the carboxylate metal salt has amelting point greater than the polymerization temperature in thereactor.

[0100] Other examples of carboxylate metal salts include titaniumstearates, tin stearates, calcium stearates, zinc stearates, boronstearate and strontium stearates.

[0101] The carboxylate metal salt in one embodiment may be combined withantistatic agents such as fatty amines, for example, Kemamine AS 990/2zinc additive, a blend of ethoxylated stearyl amine and zinc stearate,or Kemamine AS 990/3, a blend of ethoxylated stearyl amine, zincstearate and octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate. Boththese blends are available from Witco Corporation, Memphis, Tenn.

[0102] Method of Preparing the Catalyst Composition

[0103] The method for making the catalyst composition generally involvesthe combining, contacting, blending, and/or mixing of a catalyst systemor polymerization catalyst with a carboxylate metal salt.

[0104] In one embodiment of the method of the invention, aconventional-type transition metal catalyst and/or a bulky ligandmetallocene-type catalyst is combined, contacted, blended, and/or mixedwith at least one carboxylate metal salt. In a most preferredembodiment, the conventional-type transition metal catalyst and/or thebulky ligand metallocene-type catalyst are supported on a carrier.

[0105] In another embodiment, the steps of the method of the inventioninclude forming a polymerization catalyst, preferably forming asupported polymerization catalyst, and contacting the polymerizationcatalyst with at least one carboxylate metal salt. In a preferredmethod, the polymerization catalyst comprises a catalyst compound, anactivator or cocatalyst and a carrier, preferably the polymerizationcatalyst is a supported bulky ligand metallocene-type catalyst.

[0106] One in the art recognizes that depending on the catalyst systemand the carboxylate metal salt used certain conditions of temperatureand pressure would be required to prevent, for example, a loss in theactivity of the catalyst system.

[0107] In one embodiment of the method of the invention the carboxylatemetal salt is contacted with the catalyst system, preferably a supportedcatalyst system, most preferably a supported bulky ligandmetallocene-type catalyst system under ambient temperatures andpressures. Preferably the contact temperature for combining thepolymerization catalyst and the carboxylate metal salt is in the rangeof from 0° C. to about 100° C., more preferably from 15° C. to about 75°C., most preferably at about ambient temperature and pressure.

[0108] In a preferred embodiment, the contacting of the polymerizationcatalyst and the carboxylate metal salt is performed under an inertgaseous atmosphere, such as nitrogen. However, it is contemplated thatthe combination of the polymerization catalyst and the carboxylate metalsalt may be performed in the presence of olefin(s), solvents, hydrogenand the like.

[0109] In one embodiment, the carboxylate metal salt may be added at anystage during the preparation of the polymerization catalyst.

[0110] In one embodiment of the method of the invention, thepolymerization catalyst and the carboxylate metal salt are combined inthe presence of a liquid, for example the liquid may be a mineral oil,toluene, hexane, isobutane or a mixture thereof. In a more preferredmethod the carboxylate metal salt is combined with a polymerizationcatalyst that has been formed in a liquid, preferably in a slurry, orcombined with a substantially dry or dried, polymerization catalyst thathas been placed in a liquid and reslurried.

[0111] In an embodiment, the contact time for the carboxylate metal saltand the polymerization catalyst may vary depending on one or more of theconditions, temperature and pressure, the type of mixing apparatus, thequantities of the components to be combined, and even the mechanism forintroducing the polymerization catalyst/carboxylate metal saltcombination into the reactor.

[0112] Preferably, the polymerization catalyst, preferably a bulkyligand metallocene-type catalyst compound and a carrier, is contactedwith a carboxylate metal salt for a period of time from about a secondto about 24 hours, preferably from about 1 minute to about 12 hours,more preferably from about 10 minutes to about 10 hours, and mostpreferably from about 30 minutes to about 8 hours.

[0113] In an embodiment, the ratio of the weight of the carboxylatemetal salt to the weight of the transition metal of the catalystcompound is in the range of from about 0.01 to about 1000, preferably inthe range of from 1 to about 100, more preferably in the range of fromabout 2 to about 50, and most preferably in the range of from 4 to about20. In one embodiment, the ratio of the weight of the carboxylate metalsalt to the weight of the transition metal of the catalyst compound isin the range of from about 2 to about 20, more preferably in the rangeof from about 2 to about 12, and most preferably in the range of from 4to about 10.

[0114] In another embodiment of the method of the invention, the weightpercent of the carboxylate metal salt based on the total weight of thepolymerization catalyst is in the range of from about 0.5 weight percentto about 500 weight percent, preferably in the range of from 1 weightpercent to about 25 weight percent, more preferably in the range of fromabout 2 weight percent to about 12 weight percent, and most preferablyin the range of from about 2 weight percent to about 10 weight percent.In another embodiment, the weight percent of the carboxylate metal saltbased on the total weight of the polymerization catalyst is in the rangeof from 1 to about 50 weight percent, preferably in the range of from 2weight percent to about 30 weight percent, and most preferably in therange of from about 2 weight percent to about 20 weight percent.

[0115] In one embodiment, where the process of the invention isproducing a polymer product having a density greater than 0.910 g/cc,the total weight percent of the carboxylate metal salt based on thetotal weight of the polymerization catalyst is greater than 1 weightpercent. In yet another embodiment, where the process of the inventionis producing a polymer product having a density less than 0.910 g/cc,the total weight percent of the carboxylate metal salt based on thetotal weight of the polymerization catalyst is greater than 3 weightpercent. If the polymerization catalyst includes a carrier, the totalweight of the polymerization catalyst includes the weight of thecarrier.

[0116] It is believed that the more metal of the activator, for exampletotal aluminum content or free aluminum content (the alkyl aluminumcontent in alumoxane), present in the polymerization catalyst, the morecarboxylate metal salt is required. Manipulating the amounts or loadingsof the polymerization catalyst components, i.e. the free aluminum mayprovide a means for adjusting the level of carboxylate metal salt.

[0117] Mixing techniques and equipment contemplated for use in themethod of the invention are well known. Mixing techniques may involveany mechanical mixing means, for example shaking, stirring, tumbling,and rolling. Another technique contemplated involves the use offluidization, for example in a fluid bed reactor vessel where circulatedgases provide the mixing. Non-limiting examples of mixing equipment forcombining, in the most preferred embodiment a solid polymerizationcatalyst and a solid carboxylate metal salt, include a ribbon blender, astatic mixer, a double cone blender, a drum tumbler, a drum roller, adehydrator, a fluidized bed, a helical mixer and a conical screw mixer.

[0118] In an embodiment of the method of the invention, a supportedconventional-type transition metal catalyst, preferably a supportedbulky ligand metallocene-type catalyst, is tumbled with a carboxylatemetal salt for a period of time such that a substantial portion of thesupported catalyst is intimately mixed and/or substantially contactedwith the carboxylate metal salt.

[0119] In a preferred embodiment of the invention the catalyst system ofthe invention is supported on a carrier, preferably the supportedcatalyst system is substantially dried, preformed, substantially dryand/or free flowing. In an especially preferred method of the invention,the preformed supported catalyst system is contacted with at least onecarboxylate metal salt. The carboxylate metal salt may be in solution orslurry or in a dry state, preferably the carboxylate metal salt is in asubstantially dry or dried state. In the most preferred embodiment, thecarboxylate metal salt is contacted with a supported catalyst system,preferably a supported bulky ligand metallocene-type catalyst system ina rotary mixer under a nitrogen atmosphere, most preferably the mixer isa tumble mixer, or in a fluidized bed mixing process, in which thepolymerization catalyst and the carboxylate metal salt are in a solidstate, that is they are both substantially in a dry state or in a driedstate.

[0120] In an embodiment of the method of the invention aconventional-type transition metal catalyst compound, preferably a bulkyligand metallocene-type catalyst compound, is contacted with a carrierto form a supported catalyst compound. In this method, an activator or acocatalyst for the catalyst compound is contacted with a separatecarrier to form a supported activator or supported cocatalyst. It iscontemplated in this particular embodiment of the invention, that acarboxylate metal salt is then mixed with the supported catalystcompound or the supported activator or cocatalyst, in any order,separately mixed, simultaneously mixed, or mixed with only one of thesupported catalyst, or preferably the supported activator prior tomixing the separately supported catalyst and activator or cocatalyst.

[0121] As a result of using the combination of polymerizationcatalyst/carboxylate metal salt of the invention it may be necessary toimprove the overall catalyst flow into the reactor. Despite the factthat the catalyst flow is not as good as a catalyst without thecarboxylate metal salt, the flowability of the catalyst/carboxylatecombination of the invention was not a problem. If catalyst flow needsimprovement, it is well known in the art to use bin vibrators, orcatalyst feeder brushes and feeder pressure purges and the like.

[0122] In another embodiment, the polymerization catalyst/carboxylatemetal salt may be contacted with a liquid, such as mineral oil andintroduced to a polymerization process in a slurry state. In thisparticular embodiment, it is preferred that the polymerization catalystis a supported polymerization catalyst.

[0123] In some polymerization processes smaller particle size supportmaterials are preferred. However, the operability of these processes ismore challenging. It has been discovered that utilizing thepolymerization catalyst and carboxylate metal salt combination of theinvention, smaller particle size support materials may be usedsuccessfully. For example, silica having an average particle size fromabout 10 microns to 80 microns. Silica materials of this size areavailable from Crosfield Limited, Warrington, England, for exampleCrosfield ES-70 having an average particle size of 35 to 40 microns. Notwishing to bound by any theory, it is traditionally believed that usingsmaller average particle size supports produces more fines and resultsin a more sheeting prone supported catalyst. It is also believed thatthe use of a carboxylate metal salt with the polymerization catalystprovides for better particle growth during polymerization. This betterparticle morphology is believed to result in fewer fines and a reducedtendency for sheeting to occur. Thus, the use of a carboxylate metalsalt allows for the use of a smaller support material.

[0124] In an embodiment, the method of the invention provides forco-injecting an unsupported polymerization catalyst and a carboxylatemetal salt into the reactor. In one embodiment the polymerizationcatalyst is used in an unsupported form, preferably in a liquid formsuch as described in U.S. Pat. Nos. 5,317,036 and 5,693,727 and Europeanpublication EP-A-0 593 083, all of which are herein incorporated byreference. The polymerization catalyst in liquid form can be fed with acarboxylate metal salt to a reactor using the injection methodsdescribed in PCT publication WO 97/46599, which is fully incorporatedherein by reference.

[0125] Where a carboxylate metal salt and an unsupported bulky ligandmetallocene-type catalyst system combination is utilized, the mole ratioof the metal of the activator component to the metal of the bulky ligandmetallocene-type catalyst compound is in the range of between 0.3:1 to10,000:1, preferably 100:1 to 5000:1, and most preferably 500:1 to2000:1.

[0126] Polymerization Process

[0127] The catalysts and catalyst systems of the invention describedabove are suitable for use in any polymerization process. Polymerizationprocesses include solution, gas phase, slurry phase and a high pressureprocess or a combination thereof. Particularly preferred is a gas phaseor slurry phase polymerization of one or more olefins at least one ofwhich is ethylene or propylene.

[0128] In one embodiment, the process of this invention is directedtoward a solution, slurry or gas phase polymerization process of one ormore olefin monomers having from 2 to 30 carbon atoms, preferably 2 to12 carbon atoms, and more preferably 2 to 8 carbon atoms. The inventionis particularly well suited to the polymerization of two or more olefinmonomers of ethylene, propylene, butene-1, pentene-1,4-methyl-pentene-1, hexene-1, octene-1 and decene-1.

[0129] Other monomers useful in the process of the invention includeethylenically unsaturated monomers, diolefins having 4 to 18 carbonatoms, conjugated or nonconjugated dienes, polyenes, vinyl monomers andcyclic olefins. Non-limiting monomers useful in the invention mayinclude norbomene, norbomadiene, isobutylene, vinylbenzocyclobutane,styrenes, alkyl substituted styrene, ethylidene norbomene, isoprene,dicyclopentadiene and cyclopentene.

[0130] In the most preferred embodiment of the process of the invention,a copolymer of ethylene is produced, where with ethylene, a comonomerhaving at least one alpha-olefin having from 4 to 15 carbon atoms,preferably from 4 to 12 carbon atoms, and most preferably from 4 to 8carbon atoms, is polymerized in a gas phase process.

[0131] In another embodiment of the process of the invention, ethyleneor propylene is polymerized with at least two different comonomers,optionally one of which may be a diene, to form a terpolymer.

[0132] In one embodiment, the invention is directed to a process,particularly a gas phase or slurry phase process, for polymerizingpropylene alone or with one or more other monomers including ethylene,and olefins having from 4 to 12 carbon atoms. Polypropylene polymers maybe produced using particularly bridged bulky ligand metallocene-typecatalysts as described in U.S. Pat. Nos. 5,296,434 and 5,278,264, bothof which are herein incorporated by reference.

[0133] Typically in a gas phase polymerization process a continuouscycle is employed where in one part of the cycle of a reactor system, acycling gas stream, otherwise known as a recycle stream or fluidizingmedium, is heated in the reactor by the heat of polymerization. Thisheat is removed from the recycle composition in another part of thecycle by a cooling system external to the reactor. Generally, in a gasfluidized bed process for producing polymers, a gaseous streamcontaining one or more monomers is continuously cycled through afluidized bed in the presence of a catalyst under reactive conditions.The gaseous stream is withdrawn from the fluidized bed and recycled backinto the reactor. Simultaneously, polymer product is withdrawn from thereactor and fresh monomer is added to replace the polymerized monomer.(See for example U.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670,5,317,036, 5,352,749, 5,405,922, 5,436,304, 5,453,471, 5,462,999,5,616,661 and 5,668,228 all of which are fully incorporated herein byreference.)

[0134] The reactor pressure in a gas phase process may vary from about100 psig (690 kPa) to about 500 psig (3448 kPa), preferably in the rangeof from about 200 psig (1379 kPa) to about 400 psig (2759 kPa), morepreferably in the range of from about 250 psig (1724 kPa) to about 350psig (2414 kPa).

[0135] The reactor temperature in the gas phase process may vary fromabout 30° C. to about 120° C., preferably from about 60° C. to about115° C., more preferably in the range of from about 70° C. to 110° C.,and most preferably in the range of from about 70° C. to about 95° C.

[0136] Other gas phase processes contemplated by the process of theinvention include those described in U.S. Pat. Nos. 5,627,242, 5,665,818and 5,677,375, and European publications EP-A-0 794 200, EP-A-0 802 202,EP-A2 0 891 990 and EP-B-634 421 all of which are herein fullyincorporated by reference.

[0137] In a preferred embodiment, the reactor utilized in the presentinvention is capable and the process of the invention is producinggreater than 500 lbs of polymer per hour (227 Kg/hr) to about 200,000lbs/hr (90,900 Kg/hr) or higher of polymer, preferably greater than 1000lbs/hr (455 Kg/hr), more preferably greater than 10,000 lbs/hr (4540Kg/hr), even more preferably greater than 25,000 lbs/hr (11,300 Kg/hr),still more preferably greater than 35,000 lbs/hr (15,900 Kg/hr), stilleven more preferably greater than 50,000 lbs/hr (22,700 Kg/hr) and mostpreferably greater than 65,000 lbs/hr (29,000 Kg/hr) to greater than100,000 lbs/hr (45,500 Kg/hr).

[0138] A slurry polymerization process generally uses pressures in therange of from about 1 to about 50 atmospheres and even greater andtemperatures in the range of 0° C. to about 120° C. In a slurrypolymerization, a suspension of solid, particulate polymer is formed ina liquid polymerization diluent medium to which ethylene and comonomersand often hydrogen along with catalyst are added. The suspensionincluding diluent is intermittently or continuously removed from thereactor where the volatile components are separated from the polymer andrecycled, optionally after a distillation, to the reactor. The liquiddiluent employed in the polymerization medium is typically an alkanehaving from 3 to 7 carbon atoms. The medium employed should be liquidunder the conditions of polymerization and relatively inert. When apropane medium is used the process must be operated above the reactiondiluent critical temperature and pressure. Preferably, a hexane or anisobutane medium is employed.

[0139] A preferred polymerization technique of the invention is referredto as a particle form polymerization, or a slurry process where thetemperature is kept below the temperature at which the polymer goes intosolution. Such technique is well known in the art, and described in forinstance U.S. Pat. No. 3,248,179 which is fully incorporated herein byreference. Other slurry processes include those employing a loop reactorand those utilizing a plurality of stirred reactors in series, parallel,or combinations thereof. Non-limiting examples of slurry processesinclude continuous loop or stirred tank processes. Also, other examplesof slurry processes are described in U.S. Pat. No. 4,613,484, which isherein fully incorporated by reference.

[0140] In an embodiment the reactor used in the slurry process of theinvention is capable of and the process of the invention is producinggreater than 2000 lbs of polymer per hour (907 Kg/hr), more preferablygreater than 5000 lbs/hr (2268 Kg/hr), and most preferably greater than10,000 lbs/hr (4540 Kg/hr). In another embodiment the slurry reactorused in the process of the invention is producing greater than 15,000lbs of polymer per hour (6804 Kg/hr), preferably greater than 25,000lbs/hr (11,340 Kg/hr) to about 100,000 lbs/hr (45,500 Kg/hr).

[0141] Examples of solution processes are described in U.S. Pat. Nos.4,271,060, 5,001,205, 5,236,998 and 5,589,555, which are fullyincorporated herein by reference.

[0142] A preferred process of the invention is where the process,preferably a slurry or gas phase process is operated in the presence ofa bulky ligand-metallocene-type catalyst system and in the absence of oressentially free of any scavengers, such as triethylaluminum,trimethylaluminum, tri-isobutylaluminum and tri-n-hexylaluminum anddiethyl aluminum chloride, dibutyl zinc and the like. This preferredprocess is described in PCT publication WO 96/08520 and U.S. Pat. Nos.5,712,352 and 5,763,543 which are herein fully incorporated byreference. However, it has been discovered that a polymerization processutilizing the catalyst system/carboxylate metal salt combination of theinvention may be operated with a small amount of scavenger with reducedor no effect on process operability and catalyst performance. Thus, inone embodiment, the invention provides a process for polymerizingolefin(s) in a reactor in the presence of a bulky ligandmetallocene-type catalyst system, a carboxylate metal salt and ascavenger.

[0143] In one embodiment, the polymerization catalyst and/or catalystcomposition, the polymerization catalyst and the carboxylate metal salthave a productivity greater than 1500 grams of polymer per gram ofcatalyst, preferably greater than 2000 grams of polymer per gram ofcatalyst, more preferably greater than 2500 grams of polymer per gram ofcatalyst and most preferably greater than 3000 grams of polymer per gramof catalyst.

[0144] In another embodiment, the polymerization catalyst and/orcatalyst composition, the polymerization catalyst and the carboxylatemetal salt, have a productivity greater than 2000 grams of polymer pergram of catalyst, preferably greater than 3000 grams of polymer per gramof catalyst, more preferably greater than 4000 grams of polymer per gramof catalyst and most preferably greater than 5000 gram s of polymer pergram of catalyst.

[0145] In one embodiment, the polymerization catalyst and/or thecatalyst composition has a reactivity ratio generally less than 2, moretypically less than 1. Reactivity ratio is defined to be the mole ratioof comonomer to monomer entering the reactor, for example as measured inthe gas composition in a gas phase process, divided by the mole ratio ofthe comonomer to monomer in the polymer product being produced. In apreferred embodiment, the reactivity ratio is less than 0.6, morepreferably less than 0.4, and most preferably less than 0.3. In the mostpreferred embodiment, the monomer is ethylene and the comonomer is anolefin having 3 or more carbon atoms, more preferably an alpha-olefinhaving 4 or more carbon atoms, and most preferably an alpha-olefinselected from the group consisting of butene-1, 4-methyl-pentene-1,pentene-1, hexene-1 and octene-1.

[0146] In another embodiment of the invention, when transitioning from afirst polymerization catalyst to a second polymerization catalyst,preferably where the first and second polymerization catalysts are bulkyligand metallocene-type catalyst compound, more preferably where thesecond polymerization catalyst is a bridged, bulky ligandmetallocene-type catalyst compound, it would be preferable during thetransition to use a catalyst composition of a carboxylate metal saltcombined with a bridged, bulky ligand metallocene-type catalyst.

[0147] When starting up a polymerization process, especially a gas phaseprocess, there is a higher tendency for operability problems to occur.Thus, it is contemplated in the present invention that a polymerizationcatalyst and carboxylate metal salt mixture is used on start-up toreduce or eliminate start-up problems. Furthermore, it also contemplatedthat once the reactor is operating in a stable state, a transition tothe same or a different polymerization catalyst without the carboxylatemetal salt can be made.

[0148] In another embodiment, during a polymerization process that is oris about to be disrupted, a polymerization catalyst/carboxylate metalsalt mixture of the invention could be transitioned to. This switchingof polymerization catalysts is contemplated to occur when operabilityproblems arise. Indications of operability problems are well known inthe art. Some of which in a gas phase process include temperatureexcursions in the reactor, unexpected pressure changes, excessive staticgeneration or unusually high static spikes, chunking, sheeting and thelike. In an embodiment, the carboxylate metal salt may be added directlyto the reactor, particularly when operability problems arise.

[0149] It has also been discovered that using the polymerizationcatalyst combined with a carboxylate metal salt of the invention it iseasier to produce fractional melt index and higher density polymers. Inone embodiment, the invention provides for a process for polymerizingolefin(s) in a reactor in the presence of a polymerization catalyst incombination with a carboxylate metal salt to produce a polymer producthaving a melt index less than about 1 dg/min and a density greater than0.920 g/cc, more preferably the polymer product has a melt index lessthan about 0.75 dg/min and a density greater than 0.925 g/cc. Preferablythe polymerization catalyst is a bulky ligand metallocene-type catalyst,more preferably the process is a gas phase process and thepolymerization catalyst includes a carrier.

[0150] It is contemplated that using the combination polymerizationcatalyst/carboxylate metal salt of the invention, transitioning to oneof the more difficult grades of polymers would be simpler. Thus, in oneembodiment, the invention is directed to a process for polymerizingolefin(s) in the presence of a first catalyst composition, under steadystate conditions, preferably gas phase process conditions, to produce afirst polymer product. The first polymer product having a densitygreater than 0.87 g/cc, preferably greater than 0.900 g/cc, morepreferably greater than 0.910 g/cc, and a melt index in the range offrom 1 dg/min to about 200 dg/min, preferably in the range of greaterthan 1 dg/min to about 100 dg/min, more preferably from greater than 1dg/min to about 50 dg/min, most preferably from greater than 1 dg/min toabout 20 dg/min. This process further comprises the step oftransitioning to a second catalyst composition to produce second polymerproduct having a density greater than 0.920 g/cc, preferably greaterthan 0.925 g/cc, and a melt index less than 1 dg/min, preferably lessthan 0.75 dg/min. The second catalyst composition comprising, incombination, a conventional-type transition metal catalyst and/or abulky ligand metallocene-type catalyst, and a carboxylate metal salt. Itis also within the scope of this particular embodiment to transitionfrom a first polymer product having an I₂₁/I₂ (described below) of lessthan 25 to a second polymer product having an I₂₁/I₂ greater than 25,preferably greater than 30, and even more preferably greater than 35.

[0151] In yet another embodiment, the process of the invention involvesalternating between a first catalyst composition comprising a firstpolymerization catalyst/carboxylate metal salt mixture and a catalystcomposition of a second polymerization catalyst without a carboxylatemetal salt to improve the overall process operability. In a furtherembodiment, the first and second catalyst compositions described abovecan be used simultaneously, for example as a mixture or injected into areactor separately. In any of these embodiment, the first and secondpolymerization catalysts may be the same or different.

[0152] Polymer Product of the Invention

[0153] The polymers produced by the process of the invention can be usedin a wide variety of products and end-use applications. The polymersproduced by the process of the invention include linear low densitypolyethylene, elastomers, plastomers, high density polyeth'ylenes, lowdensity polyethylenes, polypropylene and polypropylene copolymers.

[0154] The polymers, typically ethylene based polymers, have a densityin the range of from 0.86g/cc to 0.97 g/cc, preferably in the range offrom 0.88 g/cc to 0.965 g/cc, more preferably in the range of from 0.900g/cc to 0.96 g/cc, even more preferably in the range of from 0.905 g/ccto 0.95 g/cc, yet even more preferably in the range from 0.910 g/cc to0.940 g/cc, and most preferably greater than 0.915 g/cc, preferablygreater than 0.920 g/cc, and most preferably greater than 0.925 g/cc.

[0155] The polymers produced by the process of the invention typicallyhave a molecular weight distribution, a weight average molecular weightto number average molecular weight (M_(w)/M_(n)) of greater than 1.5 toabout 15, particularly greater than 2 to about 10, more preferablygreater than about 2.2 to less than about 8, and most preferably from2.5 to 8. The ratio of M_(w)/M_(n) can be measured by gel permeationchromatography techniques well known in the art.

[0156] Also, the polymers of the invention typically have a narrowcomposition distribution as measured by Composition Distribution BreadthIndex (CDBI). Further details of determining the CDBI of a copolymer areknown to those skilled in the art. See, for example, PCT PatentApplication WO 93/03093, published Feb. 18, 1993 which is fullyincorporated herein by reference.

[0157] The bulky ligand metallocene-type catalyzed polymers of theinvention in one embodiment have CDBI's generally in the range ofgreater than 50% to 99%, preferably in the range of 55% to 85%, and morepreferably 60% to 80%, even more preferably greater than 60%, still evenmore preferably greater than 65%.

[0158] In another embodiment, polymers produced using aconventional-type transition metal catalyst have a CDBI less than 50%,more preferably less than 40%, and most preferably less than 30%.

[0159] The polymers of the present invention in one embodiment have amelt index (MI) or (I₂) as measured by ASTM-D-1238-E in the range from0.01 dg/min to 1000 dg/min, more preferably from about 0.01 dg/min toabout 100 dg/min, even more preferably from about 0.1 dg/min to about 50dg/min, and most preferably from about 0.1 dg/min to about 10 dg/min.

[0160] The polymers of the invention in one embodiment have a melt indexratio (I₂₁/I₂) (I₂₁ is measured by ASTM-D-1238-F) of from 10 to lessthan 25, more preferably from about 15 to less than 25.

[0161] The polymers of the invention in a preferred embodiment have amelt index ratio (I₂₁/I₂) (I₂₁ is measured by ASTM-D-1238-F) of frompreferably greater than 25, more preferably greater than 30, even morepreferably greater that 40, still even more preferably greater than 50and most preferably greater than 65.

[0162] In yet another embodiment, propylene based polymers are producedin the process of the invention. These polymers include atacticpolypropylene, isotactic polypropylene, and syndiotactic polypropylene.Other propylene polymers include propylene random, block or impactcopolymers.

[0163] Polymers produced by the process of the invention are useful insuch forming operations as film, sheet, and fiber extrusion andco-extrusion as well as blow molding, injection molding and rotarymolding. Films include blown or cast films formed by coextrusion or bylamination useful as shrink film, cling film, stretch film, sealingfilms, oriented films, snack packaging, heavy duty bags, grocery sacks,baked and frozen food packaging, medical packaging, industrial liners,membranes, etc. in food-contact and non-food contact applications.Fibers include melt spinning, solution spinning and melt blown fiberoperations for use in woven or non-woven form to make filters, diaperfabrics, medical garments, geotextiles, etc. Extruded articles includemedical tubing, wire and cable coatings, geomembranes, and pond liners.Molded articles include single and multi-layered constructions in theform of bottles, tanks, large hollow articles, rigid food containers andtoys, etc.

EXAMPLES

[0164] In order to provide a better understanding of the presentinvention including representative advantages thereof, the followingexamples are offered.

[0165] The properties of the polymer were determined by the followingtest methods:

[0166] Density is measured in accordance with ASTM-D-1238.

[0167] The Fouling Index in the Tables below illustrates operability ofthe catalyst. The higher the value the greater the fouling observed. AFouling Index of zero means substantially no or no visible fouling. AFouling Index of 1 is indicative of light fouling, where a very lightpartial coating of polymer on the stirrer blades of a 2 liter slurryisobutane polymerization reactor and/or no reactor body sheeting. AFouling Index of 2 is indicative of more than light fouling, where thestirrer blades have a heavier, painted-like, coating of polymer and/orthe reactor body wall has some sheeting in a band of 1 to 2 inches (2.54to 5.08 cm) wide on the reactor wall. A Fouling Index of 3 is consideredmedium fouling, where the stirrer blade has a thicker, latex-like,coating of polymer on the stirrer blade, some soft chunks in thereactor, and/or some reactor body sheeting with a band of 2 to 3 inch(5.08 to 7.62 cm) wide on the reactor wall. A Fouling Index of 4 isevidence of more than medium fouling, where the stirrer has a thick,latex-like, coating, some harder chunks/balls of polymer, and/or thereactor body wall sheeting band is from 3 to 4 inches (7.62 to 10.2 cm)wide.

[0168] Activity in the Tables below is measured in grams ofpolyethylene(PE) per gram of polymerization catalyst-hour (gPE/gCat.h).

Comparative Example 1

[0169] Preparation of Catalyst A

[0170] The bridged, bulky ligand metallocene-type catalyst compound usedin this Comparative Example 1 is adimethylsilyl-bis(tetrahydroindenyl)zirconium dichloride(Me₂Si(H₄Ind)₂ZrCl₂) available from Albemarle Corporation, Baton Rouge,La. The (Me₂Si(H₄Ind)₂ZrCl₂) catalyst compound was supported onCrosfield ES-70 grade silica dehydrated at 600° C. having approximately1.0 weight percent water Loss on Ignition (LOI). LOI is measured bydetermining the weight loss of the support material which has beenheated and held at a temperature of about 1000° C. for about 22 hours.The Crosfield ES-70 grade silica has an average particle size of 40microns and is available from Crosfield Limited, Warrington, England.

[0171] The first step in the manufacture of the supported bulky ligandmetallocene-type catalyst above involves forming a precursor solution.460 lbs (209 kg) of sparged and dried toluene is added to an agitatedreactor after which 1060 lbs (482 kg) of a 30 weight percentmethylaluminoxane (MAO) in toluene (available from Albemarle, BatonRouge, La.) is added. 947 lbs (430 kg) of a 2 weight percent toluenesolution of a dimethylsilyl-bis(tetrahydroindenyl) zirconium dichloridecatalyst compound and 600 lbs (272 kg) of additional toluene areintroduced into the reactor. The precursor solution is then stirred at80° F. to 100° F. (26.7° C. to 37.8° C.) for one hour.

[0172] While stirring the above precursor solution, 850 lbs (386 kg) of600 C Crosfield dehydrated silica carrier is added slowly to theprecursor solution and the mixture agitated for 30 min. at 80° F. to100° F. (26.7 to 37.8° C.). At the end of the 30 min. agitation of themixture, 240 lbs (109kg) of a 10 weight percent toluene solution ofAS-990 (N,N-bis(2-hydroxylethyl) octadecylamine ((Cl₈H₃₇N(CH₂CH₂OH)₂)available as Kemamine AS-990 from Witco Corporation, Memphis, Tenn., isadded together with an additional 110 lbs (50 kg) of a toluene rinse andthe reactor contents then is mixed for 30 min. while heating to 175° F.(79° C.). After 30 min. vacuum is applied and the polymerizationcatalyst mixture dried at 175° F. (79° C.) for about 15 hours to a freeflowing powder. The final polymerization catalyst weight was 1200 lbs(544 kg) and had a Zr wt % of 0.35 and an Al wt % of 12.0.

Example 1

[0173] Preparation of Catalyst B

[0174] A 1 kg sample of the polymerization catalyst prepared asdescribed in Comparative Example 1, Catalyst A, was weighed into a3-liter glass flask under an inert atmosphere. 40 g of Witco AluminumStearate #22 (AlSt #22) (CH₃(CH₂)₁₆COO)₂Al—OH available from WitcoCorporation, Memphis, Tenn., was dried under vacuum at 85° C. and wasadded to the flask and the contents tumbled/mixed for 20 minutes at roomtemperature. The aluminum stearate appeared to be homogeneouslydispersed throughout the catalyst particles.

Example 2

[0175] Preparation of Catalyst C

[0176] A 1 kg sample of the polymerization catalyst prepared asdescribed in Comparative Example 1, Catalyst A, was weighed into a3-liter glass flask under an inert atmosphere. 20 g of Witco AluminumStearate #22 (AlSt #22) (CH₃(CH₂)₁₆COO)₂Al—OH available from WitcoCorporation, Memphis, Tenn., was dried under vacuum at 85° C. and wasadded to the flask and the contents tumbled/mixed for 20 minutes at roomtemperature. The aluminum stearate appeared to be homogeneouslydispersed throughout the catalyst particles.

Example 3

[0177] Preparation of Catalyst D

[0178] A 1 kg sample of the polymerization catalyst prepared asdescribed in Comparative Example 1, Catalyst A, was weighed into a3-liter glass flask under an inert atmosphere. 10 g of Witco AluminumStearate #22 (AlSt #22) (CH₃(CH₂)₁₆COO)₂Al—OH available from WitcoCorporation, Memphis, Tenn., was dried under vacuum at 85° C. and wasadded to the flask and the contents tumbled/mixed for 20 minutes at roomtemperature. The aluminum stearate appeared to be homogeneouslydispersed throughout the catalyst particles.

[0179] Polymerization Process Using Catalyst A through D

[0180] A 2 liter autoclave reactor under a nitrogen purge was chargedwith 0.16 mmoles triethylaluminum (TEAL), followed by 20 cc of hexene-1comonomer and 800 cc of isobutane diluent. The contents of the reactorwere heated to 80° C., after which, 100 mg of each of the supportedpolymerization catalysts above, Catalyst A, B, C and D, were eachseparately polymerized as follows: Each polymerization catalyst wasintroduced concurrently with ethylene into the reactor to make up atotal reactor pressure of 325 psig (2240 kPa). The reactor temperaturewas maintained at 85° C. and the polymerization was allowed to proceedfor 40 min. After 40 minutes the reactor was cooled, ethylene was ventedoff and the polymer dried and weighed to obtain the polymer yield. Table1 below provides the yield activity data, as well as the foulingcharacteristics observed using Catalyst A with no aluminum stearate andCatalyst B through D, each with various levels of aluminum stearate.TABLE 1 AlSt Amount Activity Fouling Example Catalyst (g) (g PE/g Cat.h)Index Comparative 1 A  0 1845 2.0 1 D 10 1680 1.5 2 C 20 1710 0   3 B 401650 0  

[0181] Table 1 illustrates the effect of various levels of aluminumstearate on catalyst activity and operability.

Comparative Example 2

[0182] Preparation of Catalyst E

[0183] Into a 2 gallon (7.57 liters) reactor was charged first with 2.0liters of toluene then, 1060 g of 30 wt % methylalumoxane solution intoluene (available from Albemarle, Baton Rouge, La.), followed by 23.1 gof bis(1,3-methyl-n-butyl cyclopentadienyl) zirconium dichloride as a10% solution in toluene. The mixture was stirred for 60 minutes at roomtemperature after which 850 g of silica (Davison 948 dehydrated at 600°C. available from W.R. Grace, Davison Chemical Division, Baltimore, Md.)was added to the liquid with slow agitation. Stirring speed wasincreased for approximately 10 minutes to insure dispersion of thesilica into the liquid and then appropriate amount of toluene was addedto make up a slurry of liquid to solid having a consistency of 4 cc/g ofsilica. Mixing was continued for 15 minutes at 120 rpm after which 6 gof Kemamine AS-990 (available Witco Corporation, Memphis, Tenn.) wasdissolved in 100 cc of toluene and was added and stirred for 15 minutes.Drying was then initiated by vacuum and some nitrogen purge at 175° F.(79.4° C.). When the polymerization catalyst comprising the carrier,silica, appeared to be free flowing, it was cooled down and dischargedinto a nitrogen purged vessel. An approximate yield of 1 Kg of drypolymerization catalyst was obtained due to some loses due to drying.

Example 4

[0184] Preparation of Catalyst F

[0185] A sample of the polymerization catalyst prepared as described inComparative Example 2, Catalyst E, was dry blended with an amount ofWitco Aluminum Stearate #22 (AlSt #22) (available from WitcoCorporation, Memphis, Tenn.) equal to 2 weight percent based on thetotal weight of the supported polymerization catalyst. The AlSt #22 wasdried in a vacuum oven for 12 hours at 85° C. Under nitrogen, thepolymerization catalyst was then dry blended with the AlSt #22. Table 2illustrates the benefits of adding the carboxylate metal salt in theseexamples, aluminum stearate, to the polymerization catalyst. Theseexamples also show that the carboxylate metal salt has virtually noeffect on the molecular weight properties of the polymer formed.

[0186] The results of the polymerization runs for Catalysts E and Fusing the same process as previously described above for Catalysts Athrough D are shown below in Table 2. TABLE 2 Activity Amount (g PE/Fouling MI MIR Example Catalyst AlSt g Cat.h) Index (dg/min) (I₂₁/I₂)Comp. (2) B 0 1980 1.0 0.15 19.8 4 F 2 wt % 1950 0   0.18 18.0

Comparative Example 3

[0187] Preparation of Catalyst G

[0188] Into a 2 gallon (7.57 liters) reactor was charged 1060 g of 30 wt% methylalumoxane (MAO), an activator, solution in toluene (PMAO,modified MAO available from Akzo Nobel, LaPorte, Tex.), followed by 1.5liter of toluene. While stirring 17.3 g ofbis(1,3-methyl-n-butylcyclopentadienyl) zirconium dichloride, a bulkyligand metallocene-type catalyst compound, as an 8 wt % solution intoluene was added to the reactor and the mixture was stirred for 60 minat room temperature to form a catalyst solution. The content of thereactor was unloaded to a flask and 850 g of silica dehydrated at 600°C. (available from Crosfield Limited, Warrington, England) was chargedto the reactor. The catalyst solution contained in the flask was thenadded slowly to the silica carrier in the reactor while agitatingslowly. More toluene (350 cc) was added to insure a slurry consistencyand the mixture was stirred for an additional 20 min. 6 g of KemamineAS-990 (available from Witco Corporation, Memphis, Tenn.) as a 10%solution in toluene was added and stirring continued for 30 min. at roomtemperature. The temperature was then raised to 68° C. (155° F.) andvacuum was applied in order to dry the polymerization catalyst. Dryingwas continued for approximately 6 hours at low agitation until thepolymerization catalyst appeared to be free flowing. It was thendischarged into a flask and stored under a N₂ atmosphere. The yield was1006 g due to some losses in the drying process. Analysis of thepolymerization catalyst was: Zr=0.30 wt %, Al=11.8 wt %.

Examples 5 and 6

[0189] In Examples 5 and 6, the polymerization catalyst prepared asdescribed in Comparative Example 3, Catalyst G, was coinjected with 4weight percent and 8 weight percent Witco Aluminum Stearate #22, (AlSt#22) (available from Witco Corporation, Memphis, Tenn.) based on thecatalyst charge and injected into a polymerization reactor. The resultsof the polymerization runs using Catalysts G, H and I in the sameprocess as previously described for Catalysts A through D are shown inTable 3. TABLE 3 Activity AlSt (g PE/ MI (I₂) MIR Fouling ExampleCatalyst (wt %) g Cat.h) (dg/min) (I₂₁/I₂) Index Comp. (3) G 0 2535 0.1321.4 4.0 5 H 4 2250 0.12 22.5 0   6 I 8 2010 0.12 22.5 0  

[0190] Table 3 illustrates that even with a highly active, more foulingprone catalyst, aluminum stearate is effective. It further illustratesthat aluminum stearate does not materially change the productcharacteristics.

Examples 7 though 11

[0191] Examples 7 and 8 use the same catalyst from Comparative Example3, Catalyst G, with Calcium Stearate (CaSt) (Catalyst J) as thecarboxylate metal salt in Example 7 and Zinc Stearate (ZnSt) (CatalystK) in Example 8. The CaSt and ZnSt is available from MallinkrodtCorporation, Phillipsbury, N.J. The polymerization process used fortesting the catalyst compositions of Examples 7 and 8 is the same asthat described and used above for Catalyst A through D.

[0192] Examples 9 through 11 use the same catalyst from ComparativeExample 1, Catalyst A, with aluminum mono-stearate (Example 9, CatalystL) as the carboxylate metal salt, aluminum di-stearate (Example 10,Catalyst M) and aluminum tri-stearate (Example 11, Catalyst N). Thepolymerization process later described herein and used in Examples 12through 15 was used to test the catalyst compositions of Examples 9through 11, Catalysts L, M and N Table 4 below provides these results.TABLE 4 Amount of Activity Carboxylate Carboxylate (g PE/ FoulingExample Catalyst Metal Salt (wt %) g cat.h) Index Comp. (3) G None 02535 4.0 7 J CaSt 2 2295 2.0 8 K ZnSt 4 2340 3.0 Comp. (1) A None 0 18452.0 9 L Al mono-Stearate 5 NA 0   10 M Al di-Stearate 5 NA 0   11 N Altri-Stearate 5 NA 0.5

[0193] Examples 7 and 8 illustrate the use of different carboxylatemetal salts. Specifically in Examples 7 and 8, the metal of thestearate, Ca and Zn, are shown to be effective in reducing fouling.Examples 9, 10 and 11 illustrate several types of carboxylate aluminumsalts, specifically that different forms of aluminum stearate areeffective. From the data in Table 4 it can be seen that mono-stearatesand di-stearates are most effective.

Examples 12 through 15

[0194] In Examples 12 through 15 the dry blending method described inExample 1 was used with Catalyst A of Comparative Example 1 with varioustypes of carboxylate metal salts. The quantity and type of carboxylatemetal salt is set out in Table 5. The following polymerization processdescribed below was used for each polymerization catalyst/carboxylatemetal salt combination, Catalysts O, P, Q and R.

[0195] Polymerization Process for Examples 12 through 15

[0196] A 2 liter autoclave reactor under a nitrogen purge was chargedwith 0.16 mmoles triethylaluminum (TEAL), followed by 25 cc of hexene-1comonomer and 800 cc of isobutane diluent. The contents of the reactorwere heated to 80° C., after which, 100 mg of each of the supportedpolymerization catalysts/carboxylate metal salt mixture described above,(Catalyst A with the specified amounts of carboxylate metal salt asreported in Table 5), were each separately polymerized as follows: Eachpolymerization catalyst/carboxylate metal salt combination wasintroduced concurrently with ethylene into the reactor to make up atotal reactor pressure of 325 psig (2240 kPa). The reactor temperaturewas maintained at 85° C. and the polymerization was allowed to proceedfor 40 min. After 40 minutes the reactor was cooled, ethylene was ventedoff and the polymer dried and weighed to obtain the polymer yield.

[0197] The results are given in Table 5 below. Of particular interest,these Examples 12, 13, 14, and 15 illustrate a preference for having abulky R-group on the carboxylate metal salts, specifically, the aluminumcarboxylates. TABLE 5 Carboxylate Amount of Fouling Example CatalystMetal Salt Carboxylate (wt %) Index 12 O Al Acetate 5.0 4 13 P AlOctoate 5.0 3 14 Q Al Naphthenate 5.0 2 15 R Al Oleate 5.0 0

Examples 16 through 18 and Comparative Example 4

[0198] Examples 16, 17 and 18 and Comparative Example 4 illustrate theeffectiveness of the use of a carboxylate metal salt, particularlyaluminum stearate, in a fluid bed gas phase process in combination witha bulky ligand metallocene-type catalyst system to produce grades ofpolymer that are typically more difficult to produce especially in termsof operability. Traditionally, fractional melt index and higher densitygrades are difficult to make from a reactor operability standpoint. Thepolymerization catalyst used in the polymerizations of Examples 16, 17and 18 and Comparative Example 4 were run in the process described belowand the results of which are indicated in Table 6 below.

[0199] Polymerization Process

[0200] The Catalysts A, B and F described above were then separatelytested in a continuous gas phase fluidized bed reactor which comprised anominal 18 inch, schedule 60 reactor having an internal diameter of 16.5inches. (41.9 cm) The fluidized bed is made up of polymer granules. Thegaseous feed streams of ethylene and hydrogen together with liquidcomonomer were mixed together in a mixing tee arrangement and introducedbelow the reactor bed into the recycle gas line. Hexene-1 was used asthe comonomer. The individual flow rates of ethylene, hydrogen andcomonomer were controlled to maintain fixed composition targets. Theethylene concentration was controlled to maintain a constant ethylenepartial pressure. The hydrogen was controlled to maintain constanthydrogen to ethylene mole ratio. The concentration of all the gases weremeasured by an on-line gas chromatograph to ensure relatively constantcomposition in the recycle gas stream. The solid supported bulky ligandmetallocene-type catalyst system listed in Table 6, was injecteddirectly into the fluidized bed using purified nitrogen at 1.5 lbs/hr(0.68 kg/hr). The reacting bed of growing polymer particles wasmaintained in a fluidized state by the continuous flow of the make upfeed and recycle gas through the reaction zone. A superficial gasvelocity of 1 to 3 ft/sec (30.5 cm/sec to 91.4 cm/sec) was used toachieve this. The reactor was operated at a total pressure of 300 psig(2069 kPa), a reactor temperature of 85° C. and a superficial gasvelocity of 2.25 ft/sec (68.6 cm/sec) was used to achieve fluidizationof the granules. To maintain a constant reactor temperature, thetemperature of the recycle gas is continuously adjusted up or down toaccommodate any changes in the rate of heat generation due to thepolymerization. The fluidized bed was maintained at a constant height bywithdrawing a portion of the bed at a rate equal to the rate offormation of particulate product. The product is removedsemi-continuously via a series of valves into a fixed volume chamber,which is simultaneously vented back to the reactor. This allows forhighly efficient removal of the product, while at the same timerecycling a large portion of the unreacted gases back to the reactor.This product is purged to remove entrained hydrocarbons and treated witha small stream of humidified nitrogen to deactivate any trace quantitiesof residual catalyst. TABLE 6 EXAMPLE 16 17 18 Comp. 4 BTO's 9 10 8 3Catalyst B F F A Cat. Activity¹ 4300 4000 3300 4800 MI (dg/min) 0.780.73 0.43 1.47 Density (g/cc) 0.9243 0.9248 0.9230 0.9188 Resin bulk0.49 0.44 0.45 0.48 density (g/cc)

[0201] By using carboxylate metal salts in combination with thepolymerization catalysts, reactor operability improves tremendously.Table 6 illustrates a gas phase reactor operating without any problemsin producing fractional melt index polymers for many bed turnovers(BTO). Specifically shown is that using a polymerization catalystwithout the carboxylate metal salt, as in Comparative Example 4 (withoutaluminum stearate), the reactor was shut down due to fouling andsheeting in less than 3 bed turnovers at around a melt index of 1.5dg/min and a density of 0.9188 g/cc. In an embodiment of the inventionthe process is operating for a period greater than 4 bed turnovers, morepreferably greater than 5 bed turnovers and most preferably greater than6 bed turnovers. A bed turnover is when the total weight of the polymerdischarged from the reactor is approximately equal or equal to the bedweight in the reactor.

[0202] It is known in the art that reducing resin bulk density canimprove operability of a polymerization process, particularly a gasphase fluidized bed polymerization process. Note from Table 6 that theresin bulky density did not change much, however, the operability of theprocess of the invention was surprisingly, substantially improved, whena carboxylate metal salt is combined with the polymerization catalyst.

Example 19

[0203] Preparation of a Conventional-type Transition Metal Catalyst

[0204] A conventional-type transition metal catalyst was prepared from amixture of generally a magnesium compound, for example MgCl₂, a titaniumcompound, for example TiCl₃.⅓AlCl₃, and an electron donor, for exampletetrahydrofuran (THF), and was supported on silica that was dehydratedat 600° C. A detailed description of the preparation procedure can befound in U.S. Pat. No. 4,710,538, which is herein incorporated byreference. The specific catalyst formulation used had a TNHAL/THF moleratio of 29 and a DEAC/THF mole ratio of 26 where TNHAL is tri-n-hexylaluminum and DEAC is diethyl aluminum chloride.

[0205] Polymerization Process Using the Conventional-type TransitionMetal Catalyst

[0206] The dry, free flowing catalyst, described above, was injectedinto a continuous gas phase fluid bed reactor which comprised a nominal18-inch (45.7cm), schedule 60 reactor, having an internal diameter of16.5 inches (41.9cm), as described previously in this patentspecification. The same process and conditions as previously describedwere used. However, in this process, a 5 weight percent triethylaluminum(TEAL), a conventional-type cocatalyst, solution in hexane wascontinuously added to the reactor to maintain a TEAL concentration inthe fluid bed of approximately 300 ppm. Also, the solidconventional-type transition metal catalyst prepared as describeddirectly above was injected directly into the fluidized bed, see Table7, Run A.

[0207] A solution of a carboxylate metal salt, Witco Aluminum Stearate#22 (AlSt #22) in hexane (2000 ppm) was prepared. During thepolymerization process, see Table 7, Run A, the solution was pumped intothe gas phase reactor, see the results in Table 7, Run B. The catalystproductivity by material balance remained virtually the same even afterthe addition of aluminum stearate. Moreover, in this example,operability of the reactor remained stable and continued for more than 4bed turnovers before the run was voluntarily terminated. TABLE 7 Run A BAlSt #22 (ppm) 0 12.2 Cat Bulk Den (g/cc) 0.53 7 0.537 TEAL Feed (ppm)307 313 Catalyst Productivity¹ 2,947 2,836 MI (g/10 min) 13.25 13.10 MIR(HLMI/MI) 31.03 27.21 Density (g/cc) 0.9348 0.9318 Bulk Density (g/cc)0.3860 0.3834 APS (microns) 523 523

[0208] The above example illustrates that the using a carboxylate metalsalt in conjunction with a conventional-type transition metal catalystsystem the operability in a continuous gas phase polymerization processdoes not deteriorate, particularly where the carboxylate metal salt isintroduced separately from the conventional-type catalyst system.However, in some batch polymerization slurry runs it was found thatusing Witco Aluminum Stearate EA grade dry blended with aconventional-type titanium metal catalyst resulted in a reduction inproductivity. Without being bound to any particular theory, it isbelieved that the reduction in productivity may be partly due to thealuminum stearate reacting with the conventional-type cocatalyst,triethylaluminum for example, resulting in less active cocatalyst in thebatch reactor.

[0209] Examples 20 and 21 below illustrate the use of aconventional-type chromium metal catalyst dry blended with a carboxylatemetal salt.

Example 20

[0210] Preparation of a Conventional-type Chromium Metal Catalyst

[0211] A conventional-type chromium metal catalyst, also known as aPhillips-Type catalyst, was prepared using Crosfield EP510 catalyst (1wt % Titanium and 0.5 wt % Chromium—from chromium acetylacetonate)available from Crosfield Limited, Warrington, England. The EP 510catalyst was activated at 800° C. with 70% oxygen/30% nitrogen in afluidized bed column as is known in the art and was used in thefollowing polymerization process.

Comparative Example 20A

[0212] Homopolymerization Process of Ethylene

[0213] 100μ mole of triethylaluminum (25 weight percent TEAL solution inheptane) was added to a 2.2 liter autoclave reactor as a scavenger toremove trace impurities in the vessel. Polymerization grade isobutane800 ml available from Phillips Petroleum, Bartlesville, Okla., was addedto the reactor. The contents were stirred at 1000 rpm and the reactortemperature was raised from ambient to 93° C. and then ethylene wasintroduced to the reactor until the total reactor pressure was 375 psig(2586 kPag).

[0214] 300 mg of the activated chromium catalyst prepared above inExample 20 was then charged to the reactor and ethylene polymerizationproceeded for about 60 minutes at which point the reaction wasterminated by venting hydrocarbons from the reactor. In this ComparativeExample 20A the chromium catalyst as described above was used neat(without aluminum stearate) and resulted in a highly charged, staticky,polymer. A hexane solution of antistatic agent Kemamine AS-990 had to beused to remove the staticky polymer from reactor walls. The total resincollected was about 245 grams.

Example 20B

[0215] In this example, the polymerization catalyst included 300 mg ofactivated chromium catalyst (prepared as described above in Example 20)dry-blended with 15 mg of aluminum stearate, Witco Aluminum Stearate EAgrade, prior to the polymerization. The polymerization catalyst was thencharged to the reactor under the same polymerization conditions asdescribed above in Comparative Example 20A. After about 60 minutes, thepolymerization was stopped and the reactor was inspected. The resinproduced was not staticky and the polymer was easily removed from thereactor. The resin yield was 133 grams. This run demonstrated that acarboxylate metal salt, an aluminum stearate compound, either preventsor neutralizing the charges on the resin made with a conventional-typechromium metal catalyst system. It is a general belief that thereactor-sheeting phenomenon in gas phase ethylene polymerization usingchromium catalyst is related to the static charge in the system.

Examples 21 Copolymerization Process

[0216] 50 μ mole of triethylaluminum was added to the reactor as ascavenger to remove trace impurities in the vessel. Thereafter, 50 ml ofpurified hexene-1 comonomer and 800 ml of isobutane were added to thereactor. After raising the reactor temperature to 85° C. under 1000 rpmstirring, ethylene was introduced into the vessel until the pressurereached 325 psig (2586 kPag). Then, 300 mg of a polymerization catalystwas charged into the reactor and the polymerization process proceededfor a period of time. The reaction was then terminated by venting-offhydrocarbons from the reactor. The following examples were all performedusing this polymerization process. However, in some examples the amountof hexene-1 and the reaction times were different.

Comparative Example 21A

[0217] 300 mg of an activated chromium catalyst, the polymerizationcatalyst, was charged into the reactor and the polymerization process asdescribed above in Example 21 proceeded for about 60 minutes. In thisComparative Example 21A the chromium catalyst was used neat, withoutaluminum stearate, and resulted in fouling. Heavy polymer coatings wereobserved on the reactor wall, stirrer and internal thermal couple. Muchof the polymer was clumped in the bottom of the reactor. The totalamount of the sticky resin collected was 53 grams.

Example 21B

[0218] In this example, 300 mg of the activated chromium catalystprepared above in Example 20 was dry-mixed with 15 mg of aluminumstearate, Witco Aluminum Stearate EA grade. The polymerization processused was as described above in Example 21. After 50 minutes the run wasstopped by venting-off the hydrocarbons. It was found that the reactorfouling was much lighter than in Comparative Example 21A. Only a lightpolymer coating was visible on the stirrer, thermal couple and reactorwall. The total amount of resin collected was about 110 grams.

Comparative Example 21C

[0219] This Comparative Example 21C followed the same polymerizationprocess described in Example 21 except 35 ml hexene-1 was used. 300 mgof the activated chromium catalyst as described above in Example 21 wasused neat, without any aluminum stearate. The polymerization proceededfor 50 minutes, and the reactor was then vented and inspected. Severereactor fouling was observed. A ring of polymer about 3 inches (7.62 cm)wide was formed on the top of the reactor with a thickness ranging from¼ to ¾ of an inch (0.64 to 1.91 of a cm). At the bottom of the reactorwall a polymer sheet was found. The total amount of resin collected wasabout 139 grams. The polymer was too clumped to determine the polymerdensity.

Example 21D

[0220] This Example 21D followed the same polymerization processdescribed in Example 21 except 35 ml hexene-1 was used. 300 mg of thesame activated chromium catalyst used in Comparative Example 21C was drymixed with 15 mg aluminum stearate, Witco Aluminum Stearate EA grade.The polymerization proceeded for 50 minutes, and the reactor was thenvented and inspected. A very minor polymer coating was found on thestirrer, thermal couple and reactor wall. The polymer yield was 139 gramand had a density of 0.9282 g/cc.

[0221] In one embodiment, the invention is directed to a continuousprocess for polymerizing ethylene and at least one alpha-olefin havingfrom 3 to 20 carbon atoms in the presence of a polymerization catalystcomprising a conventional-type chromium metal catalyst and a carboxylatemetal salt to produce a polymer product having a density less than 0.945g/cc down to about 0.910 g/cc, preferably less than 0.940 g/cc, morepreferably less than 0.93 g/cc, even more preferably less than 0.928g/cc, and most preferably less than 0.92 g/cc. In a preferred embodimentthe continuous process is a gas phase process operating at a pressure offrom 200 psig (1379Kpa) to about 400 psig (2759 kPa) and at atemperature above 60° C., preferably 70° C., to about 120° C.,preferably the gas phase process is also operating in a condensed modewhere a liquid and a gas are introduced to a fluidized bed reactorhaving a fluidizing medium and where the level of condensed is greaterthan 8 weight percent, preferably greater than 10 weight percent andmost preferably greater than 12 weight percent up to 50 weight percentbased on the total weight of the fluidizing medium entering the reactor.For further details of a condensed mode process see U.S. Pat. Nos.5,342,749 and 5,436,304 both of which are herein fully incorporatedherein by reference.

[0222] While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For example, it is contemplated that acarboxylate metal salt can be added to reactor in addition to beingcontacted with the catalyst system of the invention. It is alsocontemplated that the process of the invention may be used in a seriesreactor polymerization process. For example, a supported bulky ligandmetallocene-type catalyst system free of a carboxylate metal salt isused in one reactor and a supported, bridged, bulky ligandmetallocene-type catalyst system having been contacted with acarboxylate metal salt being used in another or vice-versa. It is evenfurther contemplated that the components of a carboxylate metal salt, acarboxylic acid and metal compound, for example a metal hydroxycompound, may be added to the reactor or the polymerization catalyst toform in situ the reactor or with the catalyst. It is also contemplatedthat a carboxylate metal salt may be separately supported on a carrierdifferent from the polymerization catalyst, preferably a supportedpolymerization catalyst. For this reason, then, reference should be madesolely to the appended claims for purposes of determining the true scopeof the present invention.

We claim:
 1. A catalyst composition comprising, in combination, apolymerization catalyst comprising a bulky ligand metallocene catalystcompound and a metal carboxylate salt wherein the polymerizationcatalyst and the metal carboxylate salt do not form a reaction product.2. The catalyst composition of claim 1 wherein the metal carboxylatesalt is represented by the formula: MQ_(x(OOCR)) _(y) where M is a metalfrom the Periodic Table of Elements; Q is a halogen, hydroxy, alkyl,alkoxy, aryloxy, siloxy, silane or sulfonate group; R is a hydrocarbylradical having from 2 to 100 carbon atoms; x is an integer from 0 to 3;y is an integer from 1 to 4; and the sum of x and y is equal to thevalence of the metal M.
 3. The catalyst composition of claim 2 wherein yis either 1 or 2, M is a Group 2 or 13 metal, Q is a hydroxy group, andR is a hydrocarbyl radical having greater than 12 carbon atoms.
 4. Thecatalyst composition of claim 1 where the carboxylate metal salt has amelting point of from 100° C. to 200° C.
 5. The catalyst composition ofclaim 1 wherein the carboxylate metal salt is a stearate compound. 6.The catalyst composition of claim 1 wherein the carboxylate metal saltis selected from the group consisting of aluminum mono-stearate,aluminum di-stearate, aluminum tri-stearate, and a combination thereof.7. The catalyst composition of claim 1 wherein the polymerizationcatalyst is a supported polymerization catalyst comprising a carrier. 8.The catalyst composition of claim 1 wherein the polymerization catalystfurther comprises a carrier and an activator, and wherein the bulkyligand metallocene catalyst compound contains a titanium, zirconium orhafnium atom.
 9. The catalyst composition of claim 1 wherein the bulkyligand metallocene catalyst compound is represented by the formula:(C₅H_(4-d)R_(d))A_(x)(C₅H_(4-d)R_(d))M Qg-₂ wherein M is a Group 4, 5, 6transition metal, (C₅H_(4-d)R_(d)) is an unsubstituted or substitutedcyclopentadienyl derived bulky ligand bonded to M, each R isindependently hydrogen, a substituent group containing up to 50non-hydrogen atoms, a substituted or unsubstituted hydrocarbyl havingfrom 1 to 30 carbon atoms, or two or more carbon atoms joined togetherto form a part of a substituted or unsubstituted ring or ring systemhaving 4 to 30 carbon atoms, A is carbon, germanium, silicon, tin,phosphorous or nitrogen atom, or combination thereof, containing radicalbridging two (C₅H_(4-d)R_(d)) rings; each Q is independently a hydride,substituted or unsubstituted, linear, cyclic or branched, hydrocarbylhaving from 1 to 30 carbon atoms, halogen, alkoxide, aryloxide, amide,phosphide, or a univalent anionic ligand, wherein two Q's together mayform an alkylidene ligand or cyclometallated hydrocarbyl ligand or otherdivalent anionic chelating ligand, g is an integer corresponding to theformal oxidation state of M, d is an integer selected from the 0, 1, 2,3 or 4 and denoting the degree of substitution, and x is an integer from0 to
 1. 10. The catalyst composition of claim 1 wherein the weightpercent of the metal carboxylate salt based to the total weight of thepolymerization catalyst is in the range of from 0.5 weight percent to100 weight percent.
 11. A method for making a catalyst composition, themethod comprising the steps of: (a) forming a polymerization catalystcomprising a bulky ligand metallocene catalyst compound; and (b) addingat least one metal carboxylate salt.
 12. The method of claim 11 whereinthe polymerization catalyst is dry and free flowing and the metalcarboxylate metal is in a solid form.
 13. The method of claim 11 whereinthe carboxylate metal salt is represented by the formula:MQ_(x)(OOCR)_(y) where M is a metal from the Periodic Table of Elements;each Q is independently a halogen, hydroxy, alkyl, alkoxy, aryloxy,siloxy, silane or sulfonate group; each R is a hydrocarbyl radicalhaving from 2 to 100 carbon atoms; x is an integer from 0 to 3; y is aninteger from 1 to 4; the sum of x and y is equal to the valence of themetal M; Q is halogen or a hydroxy group, and R is a hydrocarbyl radicalhaving from 4 to 24 carbon atoms.
 14. The method of claim 11 where themetal carboxylate salt has a melting point of from 100° C. to 200° C.15. The method of claim 11 wherein the metal carboxylate salt is astearate compound.
 16. The method of claim 11 wherein the metalcarboxylate salt is selected from the group consisting of aluminummono-stearate, aluminum di-stearate, aluminum tri-stearate andcombinations thereof.
 17. The method of claim 11 wherein thepolymerization catalyst is a supported polymerization catalystcomprising a carrier.
 18. The method of claim 11 wherein the weightpercent of the metal carboxylate salt based to the total weight of thepolymerization catalyst is in the range of from 0.5 weight percent to100 weight percent.
 19. A method of making a catalyst composition, themethod comprising the steps of: (a) combining a polymerization catalystcomprising a bulky ligand metallocene catalyst compound with a metalcarboxylate salt.
 20. The method according to claim 19, in which thecombining period is from 1 minute to 12 hours.